Method 327 Fugitive and Area Source Measurement of Selected Volatile Organic Hazardous Air Pollutants Using Specially Prepared Canisters


Method 327

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METHOD 327 - Fugitive and Area Source Measurement of Selected Volatile Organic Hazardous
Air Pollutants Using Specially Prepared Canisters

1.0	Scope and Application

1.1	This method describes the sampling and analysis of emissions from fugitive and area sources
collected using specially prepared canisters and analyzed using a gas chromatograph (GC)
coupled with a low- or high-resolution mass spectrometer (MS) for the determination of the
airborne concentration of selected volatile organic hazardous air pollutants (oHAPs) such as
ethylene oxide or vinyl chloride.

1.2	Applicability. The use of this method is strictly intended for determining airborne
concentrations of selected speciated oHAPs to determine compliance with a fenceline emission
standard and/or work practices when specified by the applicable regulation. This method
includes data quality objectives (DQOs) specific to the measurement of airborne concentrations
of speciated oHAPs and must not be used for other compliance purposes (i.e., measurements
from ducted sources).

1.3	The analytical approach for this method uses a GC coupled with a low- or high-resolution
MS, which may consist of a linear quadrupole, ion trap, or time-of-flight (TOF) system.
Speciated oHAPs are identified by a combination of the retention times (RTs) and the associated
mass spectra by comparing observed fragmentation patterns to reference spectral patterns and
relative ion abundances established during calibration. For the speciated oHAPs, the intensity of
the observed quantitation ion in the unknown sample is compared with the system response to
the same ion for known amounts of the compound.

1.4	The sampling and analytical approach included in this method is based on previously
published EPA guidance in Compendium Method TO-15A, which describes the sampling and
analytical procedures for measuring volatile organic compounds (VOCs) in ambient air.

2.0	Summary of Method

2.1	In this method, a whole air sample is collected through a particulate filter with a flow control
device into an evacuated, specially prepared canister for a length of time specified by the
applicable regulation, typically 24 hours. After the air sample is collected, the canister valve is
closed, the canister pressure is measured, and the canister is transported to the laboratory for
analysis. Upon receipt at the laboratory, the sample collection information is verified, the
canister pressure is measured, and the canister is stored at ambient laboratory temperature until
analysis. For analysis, a known volume of the sample is directed from the canister into a
preconcentrator to collect speciated oHAPs from the sample aliquot and to allow the majority of
bulk gases (e.g., nitrogen, oxygen, argon, and carbon dioxide) and water vapor to be vented.

2.2	The laboratory, field laboratory, and field personnel must have experience with sampling
trace-level oHAPs using specially prepared canisters and with operating preconcentrator/
GC/multidetector instrumentation (e.g., MS) for trace-level analysis.

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2.3 This method is performance-based and includes a description of the equipment, instruments,
operations, and acceptance and performance criteria. EPA developed these criteria to ensure the
collection of high-quality data. Laboratories must develop their own standard operating
procedure (SOP) documents describing the equipment, equipment management, targeted
compounds, procedures, and quality assurance (QA) activities specific to that laboratory,
instrumentation, and potentially specific for the targeted analyte.

2.4 The key steps of this method required for the collection of each sample include stringent leak
testing under stop flow, using certified and clean canisters, using certified sampling devices,
collecting accurate field data, and collecting field blanks and duplicates. The key steps of this
method required for sample analysis include the analysis of blanks, use of high-quality reference
standards, and initial and ongoing calibration checks of the instruments used.

3.0 Definitions

3.1 Absolute pressure means the pressure measured with reference to absolute zero pressure,
usually expressed in units of kilopascal (kPa) absolute or pounds per square inch absolute (psia).

3.2 Collocated precision means the precision determined from the analyzed concentrations of
samples collected simultaneously from the same air mass using two discrete canisters and
collected through two separate sampling devices with separate inlets. This determines the
precision of the method including the sampling and analysis processes. Collocated precision is
determined by calculating the absolute relative percent difference (RPD) for the collocated
measurements (the absolute value of the difference between the two collocated sample results
divided by their average value and expressed as a percentage).

3.3 Continuing calibration verification sample (CCV) means single level calibration samples run
conducted periodically to confirm that the analytical system continues to generate sample results
within acceptable agreement to the current calibration curve.

3.4 Cryogen means a refrigerant used to obtain sub-ambient temperatures in the preconcentrator
and/or the GC oven. Typical cryogens are liquid nitrogen (boiling point [BP] -195.8 °C), liquid
argon (BP -185.7 °C), and liquid carbon dioxide (BP -79.5 °C).

3.5 Deionizedwater means ASTM Type I water or equivalent.

3.6 Diluent gas means hydrocarbon-free (HCF) synthetic "zero" air.

3.7 Dynamic dilution means a technique for preparing calibration mixtures in which standard
gas(es) from pressurized cylinders are continuously blended with a diluent gas (such as
humidified HCF zero air) in a mixing chamber or manifold so that a flowing stream of
calibration mixture is created.

3.8 Gauge pressure means the pressure measured with reference to the surrounding atmospheric
pressure, usually expressed in units of kPa or inches of mercury (Hg). Gauge pressure is zero-

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referenced against ambient air pressure; zero is equal to the local atmospheric (barometric)
pressure, which is nominally 101.3 kPa (29.92 in. Hg or 14.7 psia) at sea level.

3.9Mass spectrometer means an instrument that ionizes molecules and atoms (typically into
electrically charged fragments), separates these ions according to their mass-to-charge ratio (m/z
or m/e), and responds to the impact of the ions based on their population. MS systems suitable
for this method include quadrupole, ion trap, and TOF detectors. Quadrupole and ion trap MS
operating modes (i.e., full-scan, selected ion monitoring [SIM], and selected ion storage [SIS]
modes) can be selected to optimize the ion mass collection range.

3.10 Mechanical Flow Controlling Device (MFCD) means a device that is used to ensure
constant flow to an evacuated canister to near ambient pressure. MCFD are designed to maintain
a constant pressure drop (and thus a constant flow rate) across a restrictive orifice by allowing a
constant leak rate of sample into the canister as the canister vacuum decreases to near ambient
pressure without power.

3.11 Nominal concentration means a requested, target, or named concentration that approximates
the true, reference, or certified concentration. For example, a nominal 200 parts per trillion by
volume (pptv) standard may have an actual certified concentration of 206 pptv.

3.12 Preconcentrator means a device used to concentrate the target compound(s) while the bulk
gases are effectively removed. The target compound(s) are then desorbed and injected into a GC-
MS system.

3.13 Quantitative accuracy means the degree of measurement accuracy required to measure the
concentration of an identified compound, within a given tolerance of uncertainty, with an
analytical system.

3.14 Replicate precision means the precision determined from repeated analysis of a gas sample
from one canister, which may be evaluated by calculating the absolute RPD for pairwise
measurements (N = 2) or by determining the relative standard deviation (RSD) for replicate
measurements where N > 3. Replicate analyses are used to determine precision of the analysis
processes and do not provide information on sampling precision.

3.15 Second Source Calibration Verification (SSCV) Standard means a humidified calibration
standard prepared from a calibration stock gas procured from a separate supplier. An SSCV can
only be prepared with a calibration stock from the same supplier if it is unavailable from another
supplier and is prepared from a different lot of source material as the primary

calibration stock.

3.16 Static dilution means a technique for preparing calibration mixtures in which standard and
diluent gases are added to a fixed-volume vessel or chamber at a known ratio. Standard and
diluent gas amounts may be measured gravimetrically, by volume, and/or by pressure differential
from pressurized cylinders or as neat materials and blended with a known amount of diluent gas
(such as humidified zero air) in a mixing chamber or manifold.

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3.17 Target concentration means desired, estimated, or approximate concentration (see "nominal
concentration" above).

3.18 Theoretical concentration means a reference concentration derived by applying
measurements performed with calibrated instruments with known tolerances to a certified
reference standard concentration value. Measurements of the target compound(s) concentrations
are to be determined using a calibration that is developed based on theoretical concentrations.

3.19 Time-of-flight (TOF) mass spectrometry means a MS method that determines the ion's
mass-to-charge ratio by measuring the time the ion takes to reach the detector.

3.20 Wetted surfaces mean the surfaces of the flow path, canister, valving, pumps, etc., that
contact the gas undergoing collection, mixing, transfer, or analysis.

4.0 Interferences

4.1 Sample Collection. There are potential physical interferents which could impact the ability to
properly time-integrate the sampling, such as leaks of the sampling system or introduction of
foreign material (e.g., particulate matter [PM], insect nests, spider webs). These interferences are
mitigated by closely following the sampling protocols included in this method (e.g., leak check
procedures and sampling system requirements).

4.2 Canister Sampling Media Interferences. Each canister will have its own specific performance
characteristics and appropriate cleaning, sampling, and handling procedures are required for
attainment of acceptable initial and ongoing method performance. Failure to adhere to the
cleaning and certification requirements included in this method may lead to the following
interference issues:

(1) Incomplete deactivation of canister interior surfaces (e.g., canister welds) may result in active
sites for adsorption or surfaces that facilitate the decomposition of labile VOCs to form other
VOCs within the canister. Other potential sources of active sites include canister valves, valve
stems, and ferrules. Damage to the canister interior that exposes untreated surfaces may also
result in active sites.

(2) Entrained PM deposited in the canister sampling pathway can adsorb VOCs making them
unavailable in the canister gas phase which interferes with collected samples. Such trapped
VOCs can potentially desorb later and result in the inability to achieve canister cleanliness
performance specifications and/or contaminate subsequent canister sampling events.
Additionally, organic PM can react with co-sampled ozone or other oxidative species to form
target VOCs. PM can also clog tiny openings in critical or restrictive orifices, which impacts
collection flow rates.

(3) Under certain conditions, the composition of an air sample may change upon its introduction
into the canister and over time such that the air in the canister no longer represents the air
sampled. Such changes may be caused by interactions of the VOCs with the interior canister
surface or between chemicals in the air matrix. The activity of the interior canister surface is

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unique to each canister and is based on several factors, including variability in canister
manufacturing defects, differences in canister surface deactivation treatments, the presence of
PM and co-collected moisture in the canister, and artifacts from reactions of VOCs on the
canister walls.

(4) Condensed water within the canister can result in corrosion of the interior surface of canisters
with weak or deficient coatings and can result in the partitioning of hydrophilic polar VOCs to
liquid water. Under such circumstances, concentrations of these analytes in the gas phase will be
biased low until the condensation is eliminated by reduction of the canister pressure below the
vapor saturation pressure of water.

4.3 Analytical Interferences. Contamination within the analytical system may come from several
sources including, but not limited to, off-gassing of materials within the sample introduction or
preconcentrator flow path, carryover from high-concentration samples or standards, and solvent
vapors within the laboratory.

(1)	Active sites within the sample introduction or preconcentration flow path are often caused by
use of improper materials or degradation of deactivated surfaces.

(2)	Impurities in source materials or diluent gases for internal standard (IS) gas mixtures may
result in contamination of target VOCs.

(3)	Water and the delivery systems used to humidify canisters or diluent gas streams may
contaminate the canister contents or humidified gases.

(4)	Moisture in the sample gas may interfere with VOC analysis by GC-MS. Poor or inconsistent
water management during preconcentration can cause peak broadening and RT shifts that can
result in peak misidentification, particularly for hydrophilic polar compounds. Water
management systems that use semipermeable fluoropolymer membranes remove oxygenated and
polar VOCs from the sample matrix and exhibit memory effects for several VOCs. VOCs
entrained in the fluoropolymer membrane can convert to ketones and alcohols, which are
transported across the membrane bidirectionally such that these ketones and alcohols can
contaminate the sample stream and VOCs in the sample stream can be adsorbed into the
fluoropolymer and removed from the sample stream.

(5)	Carbon dioxide in the collected sample can coelute with more volatile VOCs eluting early in
the GC-MS run and interfere with their quantitation.

(6)	Artifacts in chromatograms, such as silanol compounds formed from the breakdown of
silicon-ceramic linings of canisters and siloxane compounds from the breakdown of the
stationary phase in an analytical column, can interfere with identification and quantitation of less
volatile VOCs.

(7)	Be cognizant of compounds that interfere with target analytes when operating in MS modes
that do not provide full-scan ion spectra (i.e., selected ion monitoring [SIM] and selected ion

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storage [SIS]). Such interfering coeluting compounds may share common ions, may have similar
mass spectra, and may be difficult or impossible to separate from target VOCs.

5.0 Safety

This method does not address all the safety concerns associated with its use. It is the
responsibility of the user of this standard to establish appropriate field and laboratory safety and
health practices prior to use.

6.0 Equipment and Supplies

6.1 Specially Prepared Canisters. You must use specially prepared canisters at least 6 liters in
volume that are suitable for trace gas analysis of the target compounds, such that they meet the
requirements in Section 8.3 of this method. Canisters must be able to withstand numerous cycles
of evacuation to high vacuum of 0.0067 kPa (0.002 in. Hg) and pressurization to 377 kPa (40
pounds per square inch gauge, psig).

6.2 Valves. You must use canisters with valves that are designed specifically for trace level
measurements. The wetted portions of the valve must, at a minimum, be constructed of
chromatographic-grade stainless steel (preferably type 316), and the valve seal surfaces must be
metal to metal to minimize absorption and off-gassing of VOCs and other potential
contaminants. It is recommended that valve designs have minimal internal volume and surface
area to minimize the risk of contamination.

6.3 Canister Cleaning System. You must use a canister cleaning system that includes the
following components.

6.3.1 Manifold constructed of chromatographic-grade stainless-steel tubing and connections for
multiple canisters.

6.3.2 Oil-free vacuum pump capable of achieving vacuum of approximately 3.4 kPa absolute (1
in. Hg absolute or 0.5 psia).

6.3.3 High-vacuum pump for achieving a final canister vacuum of approximately 0.0067 kPa
(0.002 in. Hg) or less.

6.3.4 Heating oven that can contain the canister and allow heating of the valve. The oven is also
used to bake sampling system components.

6.3.5 Humidification system, such as humidifier impinger or bubbler, capable of achieving
relative humidity (RH) of at least 50% in the cannister.

6.3.6 Programmable controller for selecting temperature and cycle time and for manually or
automatically switching between evacuation and pressurization.

6.3.7 A pressure release valve to minimize the likelihood of system over pressurization.

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6.3.8 Tubing and connections constructed of borosilicate glass, quartz glass, or chromatographic-
grade stainless-steel (minimum type 316 or silicon-ceramic coated) to minimize dead volume of
the system. You must not use butyl rubber or perfluoroalkoxy (PFA) materials. If needed for
connections or seals, minimize the use of Viton and Teflon to avoid adsorption and/or off-
gassing of compounds of interest or introduction of other potential interferences.

6.3.9 Purge gas such as HCF zero air or ultra-high purity (UHP)-grade cylinder nitrogen or liquid
nitrogen dewar headspace.

6.3.10 Charcoal scrubber, catalytic oxidizer, or other systems for eliminating trace contaminants
from the purge gas.

6.4 Sampling Device. The sampling device consists of the following equipment and for the
purpose of this method, the sampling device consists of the aggregation of equipment in this
section. The sampling device must be individually named with an alpha-numeric serial number
that is unique.

6.4.1 A stainless-steel particulate filter with pore size of 2 to 7 micrometers ([j,m) installed on the
sampling device inlet.

6.4.2 Sampling Probe. The internal volume of the sample probe must be less than 1% of the
volume collected by the sample container with an inverted inlet (e.g., sampling cane to prevent
the entry of water droplets) consisting of only chromatographic-grade stainless steel (including
silicon-ceramic lined steel).

6.4.3 You must use an MFCD to regulate the flow at a constant flow rate over the 24-hour
collection period into an evacuated stainless-steel canister.

6.5 Vacuum/Pressure Gauges.

6.5.1 Field Pressure Measurement Gauge. A vacuum/pressure gauge or pressure transducer with
an accuracy of ± 0.25% full scale calibrated over the range of use for the application with
sufficient resolution to permit precise measurement of pressure differentials must be used for
field sampling purposes. The accuracy of the vacuum gauge must be measured verified on an
annual basis against a National Institute of Standards and Technology (NIST)-certified standard.

6.5.2 Laboratory Canister Pressure Measurement Gauge. A vacuum/pressure gauge or pressure
transducer with an accuracy of ± 0.1% full scale or 0.13 kPa, whichever is smaller, calibrated
over the range of use for the application with sufficient resolution to permit precise measurement
of canister pressure must be used for pressurizing field samples with HCF zero air or ultrapure
nitrogen for analysis. The accuracy of the vacuum gauge must be measured verified on an annual
basis against aNIST-certified standard for analysis.

6.6 Gas Regulators. Regulators for high-pressure cylinders of dilution gas, stock standard gases,
and internal standard gases must be constructed of non-reactive material, such as high-purity

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stainless steel, and may be lined with an appropriate material that is inert to the targeted VOC
(e.g., silicon-ceramic). Do not use regulators that contain PFA materials (e.g., for seals and
diaphragms) and avoid using regulators that contain Teflon products such as polytetr-
rafluoroethylene (PTFE) and flouroethylenepropylene(FEP), where possible, to minimize
memory effects. All regulators must be rated for the pressure and flow expected during use.
Regulators must be dedicated to a specific task and labeled for use (e.g., do not use the same
regulator on a high-concentration stock VOC standard cylinder and a low-concentration stock
VOC cylinder).

Note: Some new regulators (e.g., stainless steel regulators) should be sufficiently passivated
prior to use to prevent potential sample loss.

6.7 Reference Flow Meters.

6.7.1 A flow meter (e.g., a calibrated mass flow meter (MFM), a volumetric reference standard,
or other similar measurement device) calibrated to measurement range appropriate to measure
continuous flow must be used. The flow meter must not interfere with the flow measurement
(i.e., the pressure drop across the flow meter may affect the flow being measured).

6.7.2 Reference flow meters must be calibrated on an annual basis and be able to measure within
±2 % of the predicted values (e.g., cubic centimeters per minute) against a NIST-traceable
volumetric standard.

6.8 Tubing and Fittings. Connecting tubing and fittings for dilution and standard gases must be
constructed of chromatographic-grade stainless steel (e.g., 316 type), which includes silicon-
ceramic-treated stainless steel. Connections must be metal to metal. Lines may need to be heated
to ensure that there is no condensation. You must not use PTFE thread sealants or Buna-N rubber
components on any wetted surface in a sampling and analytical system.

6.9 Analytical Instrumentation. Conduct analyses under this method using any combination of
preconcentrator, GC, and MS provided the equipment meets the performance specifications of
this method.

6.9.1 Gas Chromatographic-Mass Spectrometric (GC-MS) System.

6.9.1.1 Gas Chromatograph. The GC used for analysis under this method must allow temperature
programming with quick and accurate temperature ramping. If needed for separation of very
light VOCs from the targeted oHAPs, the GC must be capable of sub-ambient cooling (e.g., -50
°C). Carrier gas connections must be constructed of stainless-steel or copper tubing.

6.9.1.2 Chromatographic Column. The capillary chromatographic column must be capable of
achieving separation of target compounds and any potential interferences per Section 4 and
maintaining retention time stability as required in Section 9.

6.9.1.3 Mass Spectrometer. The MS may be a linear quadrupole, ion trap, or TOF unit, and must
have minimum resolution of 1 atomic mass unit (amu) or less. The MS must be capable of

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analyzing the desired mass range every 1 second or less and operate with an acquisition rate such
that at least 12 measurements are performed over a typical chromatographic peak. Quadrupole
and ion trap systems employing electron impact (EI) ionization mode must provide nominal 70
volt (V) electron energy in EI mode to produce a bromofluorobenzene (BFB) mass spectrum that
meets all the instrument performance acceptance criteria as specified in this method.

6.10 Calibration Gas Standard Preparation Equipment. This section discusses the equipment
needed to prepare working-level standards for calibrating the GC-MS by dilution of a higher
concentration stock standard gas.

6.10.1 Dynamic Dilution System Instrumentation.

6.10.1.1 The dynamic dilution system must include, at a minimum, calibrated electronic mass
flow controllers (MFCs) for the diluent gas and each standard gas to be diluted, a humidifier for
the diluent gas, and a manifold or mixing chamber where the diluent and standard gases can be
sufficiently combined before introduction to the preconcentrator or canister. The gas dilution
system must produce calibration gases whose measured values are within ± 2% of the predicted
values. The predicted values are calculated based on the certified concentration of the supply gas
(protocol gases, when available, are recommended for their accuracy) and the gas flow rates (or
dilution ratios) through the gas dilution system.

6.10.1.2 Connection tubing for the dynamic dilution system must be constructed of
chromatographic-grade or silicon-ceramic-coated stainless steel. Mixing chambers or manifolds
must be constructed of chromatographic-grade or silicon-ceramic-coated stainless steel,
borosilicate, or quartz glass.

6.10.1.3 The gas dilution system must be recalibrated once per calendar year using NIST-
traceable primary flow standards with an uncertainty < 0.25%. You must report the results of the
calibration whenever the dilution system is used, listing the date of the most recent calibration,
the due date for the next calibration, calibration point, reference flow device (device
identification [ID], signal-to-noise [S:N] ratio, and acceptance criteria.

6.10.1.4 The gas dilution system must be verified to be non-biasing under HFC zero air and
known standards at least one per calendar year for each reactive target compounds (e.g., ethylene
oxide and vinyl chloride). Zero air must be flowed through all applicable MFCs, tubing, and
manifold used and verified to not be detectable for the target compounds. Additionally, a known
standard within the calibration range of the analytical system for each target compound must be
flowed through all applicable MFCs, tubing, and manifold to allow equalization and verified to
not bias the standard by ± 15% of the concentrations in the reference sample. The equalization
time for the bias verification must be used at a minimum for the development of standards.

6.10.1.5 The gas dilution system must be verified daily or per use (whichever is less stringent)
per Section 3.2 of Method 205 using any available protocol gas and corresponding reference
method.

6.10.2 Static Dilution System Instrumentation.

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6.10.2.1	The static dilution system must include, at a minimum, a calibrated pressure transducer
or pressure gauge to measure the partial pressures of each standard gas to be diluted and the
balance gas, and a manifold to introduce the gases into the working standard canister or vessel.
Pressure transducer(s) or pressure gauge(s) used for static dilution must have an accuracy of ±
0.1% full scale or 0.13 kPa, whichever is smaller, calibrated over the range of use for the
application with sufficient resolution to permit precise measurement of pressure differentials.

6.10.2.2	Connection tubing for the static dilution system must be constructed of
chromatographic-grade or silicon-ceramic-coated stainless steel. Manifolds must be constructed
of chromatographic-grade or silicon-ceramic-coated stainless steel, borosilicate, or quartz glass.

6.10.2.3	The static gas dilution system must be recalibrated once per calendar year using NIST-
traceable primary pressure gauge with an uncertainty < 0.1%. You must report the results of the
calibration whenever the dilution system is used, listing the date of the most recent calibration,
the due date for the next calibration, calibration point, reference flow device (ID, S:N ratio), and
acceptance criteria.

6.10.2.4	The gas dilution system must be verified to be non-biasing under HFC zero air and
known standards at least one per calendar year for each reactive target compounds (e.g., ethylene
oxide and vinyl chloride). Zero air must be flowed through all applicable tubing and manifold
used and verified to not be detectable for the target compounds. Additionally, a known standard
within the calibration range of the analytical system for each target compound must be flowed
through all applicable tubing and manifold into the standard canister or vessel and verified to not
bias the standard by ± 15% of the concentrations in the reference sample.

6.11 Calibrated Hygrometer.

6.11.1	The calibrated hygrometer must be capable of a 1% RH resolution with a yearly
calibration to a NIST-traceable accuracy of ± 3% RH within the range of 20% to 80% RH.

6.11.2	The calibration hydrometer calibration must be verified weekly or per use (whichever is
less stringent) at a single point that is approximatively 40 to 50% RH to within ± 5% using a
second calibrated hygrometer or a saturated salt solution.

7.0	Reagent and Standards

7.1	You must use only NIST-certified or NIST-traceable calibration standards, standard
reference materials, and reagents that are stable through certification and recertification for the
tests and procedures required by this method. You must use standards and reagents within their
expiration period and evaluate working-level standards prepared in canisters within 30 days of
preparation. The concentrations of the target compounds in the mixture must be commensurate
with the anticipated dilution factor achievable by the laboratory needed to dilute the mixture to
the desired working range. You must retain and report the gas standard certificates of analysis.

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7.2 Carrier Gas. Use helium, hydrogen, or nitrogen as the carrier gas in the GC. Carrier gas must
be ultrapure (99.999% pure or better).

7.3 HCF Zero Air. Purchase HCF zero air in high-pressure cylinders from reputable gas vendors
or prepare HCF zero air by passing ambient air through molecular sieves, catalytic oxidizers, and
subsequent charcoal filters or similar substrate. HFC zero air must contain impurities less than 20
pptv or undetected (whichever is more stringent) per compound of interest.

7.5 Nitrogen. Use ultrapure (99.999% pure or better) nitrogen from cylinders procured from
commercial gas vendors or from the headspace gas from a liquid nitrogen dewar.

7.6 Cryogens. Cryogens (e.g., liquid nitrogen, liquid argon, and liquid carbon dioxide) specified
by the instrument manufacturer, if needed.

7.7 Water for Canister Humidification. ASTM Type I (resistivity >18 megaohm-centimeter
[MOxm]) or equivalent.

8.0 Sample Collection and Preparation

This section presents the sample collection and handling procedures of this method with the
initial and ongoing performance evaluation of materials used in sampling and analysis. This
method allows the user to choose the materials used for sampling. You must record the exact
materials used when conducting this method and include that information in any report
associated with sampling according to this method.

8.1 Sampling Device Performance Tests. Prior to initial field deployment and as directed in this
section, you must verify that all equipment used to conduct this method meets the performance
criteria specified in this section. The primary objectives of the performance tests in this section
are to characterize the sampling system and to verify that the sampling system used meets the
criteria in the method. The sampling system performance tests include the following:

(a)

Flow control verification test,

(b)

Flow control flow check,

(c)

Sampling device leak check,

(d)

Sampling device bias check, and

(e)

Sampling device standard check.

8.1.1 Flow Control Verification Test. Prior to initial field deployment and at least every six
months, you must verify that the sampling device's ability to control flow to the canister is
acceptable. Assemble an evacuated canister with the sampling device including filter connected
to a certified flow meter. Figure 1 of Section 17 of this method provides an illustration of the
apparatus for characterizing the flow control device.

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8.1.1.1 Open the evacuated canister, monitor and record (manually or electronically) the canister
pressure downstream of the flow control device and the flow upstream of the flow control device
on an hourly basis over the period of 24-hours.

8.1.1.2 The flow control verification test is considered acceptable when the sampling apparatus
maintains a constant flow rate for 24-hours and until at least 75% of the canister volume is
collected, which is equivalent to approximately 28 kPa (7 in. Hg or 4 psia) below atmospheric
pressure.

8.1.1.3 Record the average flow rate during this test. This value will be the reference flow rate
for the sampling device until the next verification test. Maintain the results as part of a laboratory
record associated with the sampling device.

8.1.2 Flow Control Flow Check. Prior to and after each field sampling event, establish or verify
the flow rate of the sampling apparatus. This verification must occur in the field immediately
prior to and after each field event.

8.1.2.1 Assemble an evacuated canister and the sampling device connected to a certified flow
meter in the same manner used for the flow control verification test discussed above.

8.1.2.2 Open the evacuated canister, allow sufficient time for the system to stabilize, and record
the flowrate upstream of the flow control device. Collect two additional flow rate measurements.

8.1.2.3 Calculate the average flowrate. The flow control flow check is considered valid if within
+/- 10% of the reference flow rate.

8.1.2.4 If the flow rate has changed and is outside the desired range, you must adjust the
controller and repeat the flow check.

8.1.3 Sampling Device Leak Check. You must demonstrate the sampling device and sampling
system are leak-free immediately before you begin sampling.

8.1.3.1 Install the sampling device on an evacuated canister equipped with a MFCD and tightly
cap the inlet to the sampling device.

8.1.3.2 Open the canister valve fully, and then re-close the valve and observe the
vacuum/pressure gauge for a minimum of 2 minutes.

8.1.3.3 If you observe an increase in pressure, the sampling device does not qualify as leak-free.
If no changes are observed, record the data and time of the leak check on the Field Data Page
(see Figure 4 in Section 17 of this method for an example).

8.1.4 Sampling Device Bias Check. You must demonstrate that sampling device is non-biasing
under zero-air and known-standard conditions. For the procedures in Sections 8.1.5 and 8.1.6 of

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this method, you must use only canisters that have been qualified as specified in Section 8.3 of
this method.

8.1.5 Zero-Air Challenge. You must conduct the sample bias test at least every six months, and
after cleaning, replacement of components, or collection of potentially contaminating samples.
The volume of air analyzed for the zero-air and reference standard gas must be consistent with
the laboratory's typical canister sample injection volume.

8.1.5.1 Provide humidified (> 40% RH) HCF zero air through the sampling device into the
canister, and then analyze the sample according to Section 11 of this method and record the
concentration measurement and maintain the results as part of a laboratory record associated
with the sampling device.

8.1.5.2 Provide humidified (> 40% RH) reference standard air through the sampling device into a
canister, then analyze the sample according to Section 11 of this method and record the
concentration measurement and maintain the results as part of a laboratory record associated
with the sampling device.

8.1.5.3 The results must show that the concentration of the target compounds in the zero-air
challenge sample collected through the sampling unit is not greater than 20 pptv higher than the
native concentration of the target compounds in the reference sample. If a sampling device does
not meet this performance criteria, take action to remove the contamination attributable to the
sampling unit (e.g., purging with humidified HCF zero air overnight or longer) and repeat the
zero-air challenge. You must not use a sampling device that has not met the standards in this
section.

Note: If extended purging durations are not adequate to eliminate contaminants, then
disassemble and clean according to Section 8.4 of this method. If the unit cannot be cleaned to
meet the specifications, retire the unit from use or repurpose for source sampling.

8.1.6 Sampling Device Standard Check. You must conduct the sampling device standard check
prior to initial use and at least every six months, and after replacement of components, or
collection of potentially contaminating samples. For the procedures specified below, you must
use only canisters that have been qualified as specified in Section 8.3 of this method.

8.1.6.1 Collect a humidified (> 40% RH) known-standard challenge gas through the sampling
device and into a canister. The challenge gas must contain the target oHAPs at 100 to 500 pptv
each and you must choose the selected challenge concentration considering the expected
measured concentration at the deployment location(s).

8.1.6.2 Analyze the sample according to Section 11 of this method and record the concentration
measurement and maintain the results as part of a laboratory record associated with the sampling
device. The results must demonstrate that each oHAP in the sample collected through the
sampling device must be within ± 15% of the concentrations in the reference sample. For
compounds exceeding this criterion, you must take steps to eliminate the bias (e.g., cleaning as

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specified in Section 8.6.1 of this method or replacement of compromised parts) and repeat the
known-standard challenge.

8.1.6.3 Following successful completion of the known-standard challenge, flush the sampling
device or system with humidified (> 50% RH) HCF zero air or ultrapure nitrogen for a minimum
of 24 hours before field deployment.

8.2 Qualification of Analytical Instrumentation. Prior to initial use and as directed in this section,
you must verify that the analytical equipment used in performing this method meets the
performance criteria in this section. The primary objectives of these performance tests are to
characterize the analytical instrumentation and verify that the analytical instrumentation meets
the criteria in this method. The analytical instrumentation performance tests consist of the
following:

(a) Analytical zero-air verification,

(b) Analytical known-standard challenge for analytical instrumentation, and

8.2.1 Analytical Zero-Air Verification. Prior to initial use and as part of an instrument's annual
calibration, you must demonstrate that the analytical instrumentation (preconcentrator, GC-MS
system, and all connections) is non-biasing under zero-air. The volume of air analyzed must be
consistent with the laboratory's typical canister sample injection volume.

8.2.1.1 Use the analytical instrumentation to analyze humidified (40 to 50% RH) HCF zero air
from a known clean source (e.g., certified clean canister, clean cylinder gas, zero-air generator)
at the installation prior to initial use of the instrument.

8.2.1.2 Examine chromatograms for interferences and other chromatographic artifacts such as
nontarget peak responses, large peaks or rises in the chromatogram due to undifferentiated
compounds, and baseline anomalies. The analysis must show that the concentration of any
detected target compounds in the zero-air challenge sample is < 20 pptv or undetected
(whichever is more stringent) per compound of interest.

8.2.1.3 If you identify exceedances of target compounds in the zero-air challenge, take steps
(e.g., analyzing replicates of humidified clean gas until the contamination is eliminated) to
remove the contamination attributable to the analytical instrumentation by following the
manufacturer's instructions.

8.2.1.4 You must repeat the analytical zero-air verification to ensure that you have mitigated any
problems before using the analytical instrumentation.

8.2.2 Analytical Known-Standard Challenge for Analytical Instrumentation. Prior to initial use
and as part of an instrument's annual calibration, you must demonstrate that the analytical
instrumentation (preconcentrator, GC-MS system, and all connections) is non-biasing under

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known standards. The volume of air analyzed must be consistent with the laboratory's typical
canister sample injection volume.

8.2.2.1 Analyze a humidified (40 to 50% RH) reference standard in duplicate containing all
target compounds at approximately 100 to 500 pptv each, chosen in consideration of the
expected concentration at the deployment locations.

8.2.2.2 The results must demonstrate that the target compounds in the sample collected through
the sampling device are within ± 15% of the expected concentrations in the sample.

8.2.2.3 Compounds demonstrating poor response as indicated by peak absence or minimal peak
area may be a result of active sites in the analytical system, cold spots in transfer lines, gas
impurities, improper choice of preconcentrator sorbent traps or GC columns, system leaks,
and/or poor moisture management. If you identify problems, consult the instrument manufacturer
to determine the necessary steps to eliminate the bias.

8.2.3 Autosampler Verification. Prior to initial use and as part of an instrument's annual
calibration, you must demonstrate that the auto sampling equipment is non-biasing under zero-
air.

8.2.3.1 If you use an autosampler to facilitate analysis of multiple canisters, you must test all
ports, transfer lines, and connections of the autosampler after you have calibrated the analytical
system and prior to conducting the canister, sampling device and system qualifications, or upon
replacement of transfer lines or after analysis of potentially contaminating samples.

8.2.3.2 Connect humidified (40 to 50% RH) HCF zero air to each port and verify that the
concentration for each target compound is < 20 pptv or undetected (whichever is more stringent)
per compound of interest using the procedures in Section 11 of this method.

8.2.3.3 After the zero-air test, challenge each port of the autosampler with a reference standard
(approximately 100 to 500 pptv) to verify that the autosampler is not causing bias using the
procedures in Section 11 of this method). The concentration of each target compound must be
within ± 15% of the theoretical concentration of the reference standard.

8.3 Qualification of Canisters. Prior to initial use and as directed in this section, sampling
canisters must meet the performance criteria in this section. The primary objectives of these
performance tests are to ensure canisters are well characterized and to verify they are non-
biasing. The performance criteria in this section are specific to the application of fenceline
measurements for regulatory purposes at stationary sources. The performance test consists of the
following:

(a) Canister design,

(b) Canister leak check,

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(d) Canister known-standard verification.

8.3.1 Canister Design.

8.3.1.1 You must use specially prepared canisters at least 6-liters volume in size that are suitable
for trace gas analysis of the target compounds. The canister must include a fixed on/off valve
made from chromatographic-grade stainless with metal valve seal surfaces. Each canister must
also include a permanent alpha-numeric serial number for identification purposes. Alternative
canister volumes may be used, subject to approval by the Administrator.

Note: Specially prepared canisters are commercially available with a modest range of options
for surface preparation of the canister interior surfaces, valves, and connections. Currently,
canister interior surfaces are typically passivated by electropolishing or coating with a silicon-
ceramic film. EPA does not require a specific treatment or design and any canister type may be
usedfor this method contingent on meeting the performance criteria in this section; however,
silicon-ceramic coated canisters have demonstrated superior performance when used to sample
reactive compounds, (e.g., ethylene oxide).

8.3.1.2 Canisters should be handled with care to ensure that the interior canister surface is not
compromised, the valve-to-canister connection remains intact, and weld integrity is maintained.
Excessive torque on unbraced canister valve stems when making connections may cause damage
and potentially leaks in the valve stem weld or at the ferrule sealing the canister valve and
canister stem. Shocks resulting in dents to the surface of the canister may damage welds or create
small cracks in the interior canister surface that may expose active sites. You must not use any
canister with dents or compromised welds.

8.3.1.3 You must maintain a record of the results for all canisters used for this method. It is
recommended that you evaluate the results for any potential trends that could result in erroneous
data.

8.3.2 Canister Leak Check. You must qualify each canister as being acceptably leak-tight to
ensure sample validity. Qualify new canisters before initial use and qualify all canisters used for
sampling at least annually.

8.3.2.1 Leak Check. In conducting the canister leak check, you can either evacuate the canister to
high vacuum < 0.0067 kPa absolute (0.002 in. Hg or 0.001 psia) or pressurize the canister with
clean fill gas to > 203 kPa absolute (60 in. Hg or 29.4 psia).

8.3.2.2 After establishing the target pressure in the canister, close the valve and attach a
vacuum/pressure gauge.

8.3.2.3 Open the valve and record the initial pressure reading.

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8.3.2.4 Close the valve, remove the vacuum/pressure gauge, and loosely cap the canister using a
cap fitting to ensure that leakage through the valve is accurately assessed while avoiding
potential entry of debris into the valve during storage.

8.3.2.5 After a minimum of three days in storage, reinstall the vacuum/pressure gauge, open the
valve, and record the canister pressure reading.

8.3.2.6. Determine the pressure decay rate as the absolute value of the difference between the
initial and post-storage canister pressures. You must remove the canister from service if the
pressure decay rate exceeds 0.69 kPa/storage day (0.2 in. Hg or 0.1 psia/storage day).

8.3.3 Canister Zero-Air Verification. You must qualify each canister as being acceptably non-
biasing under zero-air conditions to ensure sample validity. Qualify new canisters before initial
use and qualify all canisters used for sampling at least once every 6 months.

8.3.3.1 Pressurize the clean evacuated canister with humidified (> 50% RH) HCF zero air. Do
not use ultrapure nitrogen to pressurize the canister because the inert nitrogen atmosphere does
not permit reactions within the canister that may occur under sampling conditions.

8.3.3.2 Allow the canister to equilibrate for a minimum of 24 hours.

8.3.3.3 After the equilibration period, conduct an initial cleanliness analysis as specified in
Section 8.4 of this method.

8.3.3.4 Store the canister for a holding period equal to or exceeding the typical laboratory
holding time, nominally 7 days from the canister fill date.

8.3.3.5 After the holding period, conduct a subsequent cleanliness analysis as specified in
Section 8.5 of this method.

8.3.3.6 The results of both the initial and subsequent cleanliness analysis must meet the
cleanliness criteria specified in Section 8.5 of this method to be used for sampling. You must
reclean and retest canisters that fail the zero-air challenge.

Note: If necessary, use more aggressive cleaning techniques such as water rinses or other rinses
as specified by manufacturers. If a canister continues to fail the zero-air challenges, remove the
canister from service.

8.3.4 Canister Known-Standard Verification. You must qualify each canister as being acceptably
non-biasing under known-standard conditions to ensure sample validity. Qualify new canisters
before initial use and qualify all canisters used for sampling at least every 6 months.

8.3.4.1 Fill the clean evacuated canister with a humidified (40 to 50% RH) standard gas in HCF
zero air with each target compound at approximately 100 to 500 pptv. Choose the selected
challenge concentration based on the concentration expected to be measured during the sampling
event.

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8.3.4.2 Allow the canister to equilibrate for a minimum of 24 hours.

8.3.4.3 After the equilibration period, conduct an initial analysis according to Section 11 of this
method.

8.3.4.4 Store the canister for a holding period equal to or exceeding the typical laboratory
holding time, nominally 7 days from the canister fill date.

8.3.4.5 After the holding period, conduct a subsequent analysis.

8.3.4.6 The results of both the initial and subsequent analysis must show that the measured
concentrations of the target analytes are within ± 30% of the theoretical spiked concentration for
each target compound. You must reclean and retest canisters that fail the known-standard
verification.

8.4 Canister Cleaning. Clean canisters using repeated cycles of evacuation and pressurization.
Table 1 in Section 17 of this method summarizes the canister cleaning procedures.

8.4.1 Gas Source for Canister Cleaning, Pressurization, and Flushing.

8.4.1.1 Verify, by direct analysis, the cleanliness of the purge gas upon initial setup. The analysis
must show that the concentration of the individual target compounds is < 20 pptv or undetected
(whichever is more stringent) per compound of interest at 101.3 kPa absolute (29.92 in. Hg or
14.7 psia).

8.4.1.2 Humidify the purge gas to >50% RH and measure the humidity by placing a calibrated
hygrometer probe in the humidified gas stream.

8.4.1.3 If using a bubbler-type humidifier, ensure that the downstream pressure is lower than the
humidifier upstream pressure to avoid backflow of the water.

8.4.2 Pre-Evacuation of Canisters. You may need to repeat the pre-evacuation process for
canisters that contain VOCs at higher concentrations.

8.4.2.1 Pre-evacuate canisters to be cleaned prior to connection to the canister cleaning system.
To reduce the potential for contamination of the system, attach the canisters to an oil-free
roughing pump and evacuate to approximately 7 kPa absolute (28 in. Hg vacuum or 1.0 psia)
with the exhaust of the pump directed to a fume hood or passed through a charcoal trap.

8.4.2.2 Refill canisters to ambient pressure with HCF zero air.

8.4.2.3 Attach the canisters to the cleaning system after completing the pre-evacuation and
refilling steps.

8.4.3 Canister Heating During Cleaning.

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8.4.3.1 Heat canisters by placing them in an enclosed oven during cleaning to facilitate removal
of compounds. Do not use heat bands or heating jackets.

8.4.3.2 Table 1 of Section 17 of this method specifies the temperatures to use for canister
cleaning procedures.

8.4.4 Canister Evacuation and Pressurization Cycling.

8.4.4.1 Evacuate canisters to minimally 7 kPa absolute (28 in. Hg vacuum or 1 psia) and
maintain this vacuum for a at least 1 minute.

8.4.4.2 Pressurize canisters to 414kPa absolute (< 30 psig) with humidified (> 50% RH) HCF
zero air and maintain this pressure for a minimum of 1 minute.

8.4.4.3 Repeat the cycle of canister evacuation and pressurization specified in Sections 8.4.4.1
and 8.4.4.2 of this method at least 5 times. You may need to perform 10 to 20 cycle repetitions or
use other ancillary procedures to remove stubborn interferents or oxygenated compounds such as
ketones, alcohols, and aldehydes (U.S. EPA, 2016b).

8.5 Verification of Canister Cleanliness Prior to Sample Collection.

8.5.1 After cleaning, pressurize each canister from the batch with humidified HCF zero air and
maintain that pressure for at least 24 hours.

8.5.2 Connect each canister to the analytical system and measure the concentration of each target
compound according to the procedures in Section 11 of this method.

8.5.3 The canister background concentration for each target compound must be < 20 pptv (0.02
ppbv) or undetected (whichever is more stringent) when a canister is filled to standard ambient
pressure (101.3 kPa absolute or 14.7 psia).

8.5.4 Canisters that meet the blank criteria are suitable to be evacuated for use. If a canister fails
to meet the criteria, you must not use that canister until it has been re-cleaned and has met the
requirements in Section 8.5.3 of this method.

8.5.5 Prior to field deployment, evacuate canisters to < 0.0067 kPa (< 0.002 in. Hg or 0.001 psia)

8.6 Cleaning of Sampling Components.

8.6.1 Follow the manufacturer's instructions for cleaning components such as flow controllers
and sampling unit parts, when necessary.

Note: Disassembly of such instruments may void warranties or calibrations.

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8.6.1.1 Flush the sampling units with humidified HCF zero air to remove contamination for at
least 15 minutes.

8.6.1.2 Disassemble sampling components and visually inspect for cracks, abrasions, and residue
prior to sonicating in deionized water for at least 30 minutes.

8.6.1.3 After flushing/sonication, rinse the components with clean deionized water and dry the
components in an enclosed oven set to at least 50 °C for a minimum of 12 hours.

8.6.1.4 Following drying, reinspect components for defects, reassemble, and flush the sampler
with humidified HCF zero air or ultrapure nitrogen for at least 12 hours.

Note: To avoid damage to deactivated stainless-steel components due to oxidation in the
presence of oxygen-containing atmospheres (e.g., HCF zero air), you should not heat
components treated with silicon-ceramic coatings above 80 °C unless evacuated or under an
inert atmosphere (e.g., nitrogen).

8.7 Sample Collection. Persons collecting field samples should be familiar with all aspects of this
sampling protocol. It is suggested that those collecting these measurements for regulatory
purposes develop site-specific SOPs to ensure samples are collected consistently and those doing
the sampling are sufficiently trained on this method and the SOP.

8.7.1 Pre-Sampling Activities.

8.7.1.1 Clean canisters and verify that the canisters meet cleanliness and vacuum criteria
specified in Sections 8.3 through 8.5 of this method.

8.7.1.2 If canisters were previously cleaned and stored under pressure while awaiting use, you
must evacuate the canisters prior to field deployment. If canisters were stored under vacuum, you
must verify that the canisters continue to meet vacuum threshold requirements.

8.7.1.3 Clean and verify the cleanliness and flowrates of sample devices that you will use for
sampling, and ensure that a clean particulate filter is placed in the inlet of the sampling device.

8.7.1.4 Establish sample codes (unique identifiers) and develop field data page and/or chain of
custody (COC)/sample collection data form(s).

8.7.1.5 If shipping equipment into the field, make sure you have the proper number of canisters
and sampling devices for the number of samples required for the sampling location and QC
samples, allowing for sufficient timing for samples to arrive at the site.

8.7.1.6 Develop a unique sampling location ID. The sampling location must meet any
requirements set in the applicable regulation and be in a secure location that protects the canister
and sampling inlet from unwanted tampering or damage. The sampling location must also be
located away from the immediate vicinity of any biasing sources (e.g., outdoor smoking areas;
vehicle exhaust; heating, ventilation, and air conditioning units/building exhaust; outdoor fuel

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storage areas; shelter roofing materials; or exhaust from other sample collection devices). In
general, horizontal distances should be > 10 meters (m) from biasing sources.

8.7.2 Sample Setup Activities.

8.7.2.1 You must place the canister in a location that protects the canister and sampling inlet
from unwanted tampering, damage, or theft.

8.7.2.2 Protect the canister and sampling inlets by placing the canister under shelter, if possible.
Do not restrict air flow around inlets and do not locate inlets under building overhangs.

8.7.2.3 Do not place the canister near vegetation or structures that block or significantly restrict
air flow to the MFCD inlet or manifold. Ensure that rain cannot be drawn directly into the
MFCD, and the inlet heights must be approximately 1.5 to 3 m above ground level.

8.7.3 Sample Setup and Deployment. Perform the following steps at the time of sample setup and
deployment.

8.7.3.1 Based on the applicable standard, determine the appropriate number and placement of
sampling locations at the fenceline. The applicable standard will define the sampling schedule
(e.g., one sampling event over a 5-day period) and the sampling period. All sampling locations
must initiate sampling within 60 minutes of each other.

8.7.3.2 You must document all activities associated with sampling on the field data page. (See
Figure 4 in Section 17 of this method for an example field data page.) You may choose to use
this field data page as the COC, or you may choose to establish a separate COC form. The chain
of custody will accompany the canisters during shipment and collection to document sample
handling and transport.

8.7.3.4 Verify that each canister has been cleaned and blanked within the last 30 days. Label
each canister with a sample ID code and record the canister and sample ID on the field data page.
You must not use a use a canister for sampling that has not been cleaned and blanked within 30
days of sampling.

8.7.3.5 Verify the sample device is in working order and calibrate/verify the flow rate setting, if
applicable, with a reference flow meter. Record the sample device ID, expected flowrate, and the
reference flowrate if calibrated/verified in the field, including the reference flow meter if
applicable.

8.7.3.6 Attach the sampling device to the canister and locate at the appropriate sampling location.
Record the sampling location ID, latitude, longitude, date, and time that you installed the canister
on the field data page.

8.7.3.7 Measure and record the canister vacuum using the field pressure measurement gauge, and
verify that the canister has not leaked and has sufficient vacuum to collect the sample. You must

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replace the canister if the initial pressure is not within -1 in. Hg absolute zero (-3.39 kPa
or -0.5 psi).

8.7.3.8 Conduct leak checks as specified in Section 8.3.2 of this method and record the results on
the field data page.

8.7.3.9 Open the canister valve. Record the date and time that you opened the valve as the start
time, and record the initial canister vacuum/pressure and any other comments such as unusual
events or conditions that may impact sample results on the field data page.

8.7.3.10 Sample for the period as defined in the applicable standard (e.g., 24 hours +/- 1 hour).

8.7.3.11 At the end of the sampling period, close the valve. Record the date and time that you
closed the valve as the end time.

8.7.3.12 Remove the sampling device and attach the field pressure measurement gauge.

8.7.3.13 Open the canister valve and measure and record the final canister vacuum/pressure and
any other comments such as unusual events or conditions that may impact sample results on the
field data page. Flag any canisters with a final pressure greater than -3 in. Hg gauge pressure
(-10.2 kPag or -1.5 psig).

8.7.3.14 Disconnect the field canister pressure measurement gauge and replace with a cap.

8.7.3.15 If applicable, verify the sample device is still in working order and verify the flow rate
setting with a reference flow meter. Record the final flowrate on the field data page.

8.7.4 Field Duplicates. For each sampling day, you must include the collection of a separate co-
located sample for at least one sampling location. The collocated duplicate must be sampled
using a discrete MFCD. The collection of the field duplicates must follow the same procedure
and occur at the same time as the co-located field sample.

8.7.5 Canister Field Blanks. For each sample day, you must collect canister field blanks. A
canister blank is prepared by filling a canister with humidified clean diluent gas (prepared in the
same manner as the method blank (MB) described in Section 9.3.2 of this method) to
approximately -15 in. Hg ± 1 in. Hg . Record the pressure and transport to the field site(s) to
accompany field-collected canisters. Canister field blanks are to be treated identically to field-
collected samples in the field and laboratory including pressure checks, MFCD leak checks, etc.
The field blanks are analyzed by interspersing them among the field samples.

8.7.6 Canister Field Spike. For each sample day, you must collect a canister field spike. A
canister field spike is prepared by filling a canister with humidified standard gas at a
concentration in the lower third of the calibration curve for the target compound to
approximately -15 in. Hg ± 1 in. Hg. The field spike canister is transported to the field site to
accompany field-collected canisters and treated identically to field-collected samples in the field
and laboratory, including pressure checks, MFCD leak checks, etc. The field spikes are analyzed

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by interspersing them among the field samples. Field spike acceptance criteria should be within
± 30% of the theoretical spiked concentrations.

8.7.7 Prepare and secure the canisters for transport. You must ship canisters in protective hard-
shell boxes and/or sturdy cardboard boxes to ensure canister longevity. Do not use boxes that
have lost integrity or rigidity.

8.8 Method Detection Limit (MDL) Determination. Determine the MDL under the analytical
conditions selected (see Section 11 of this method) using the procedures in this section.

8.8.1 Prepare at least seven blank samples according to the procedures Section 9.3.2 of this
method using sampling media (i.e., canisters) that have been deployed in the field, and cleaned
per Section 8.4 of this method. The blank samples must be prepared in at least three batches on
three separate calendar dates and analyzed on three separate calendar dates according to the
procedures in Section 11 of this method.

8.8.2 Prepare at least seven spike samples according to the procedures in either Section 10.2 or
10.3 of this method, at a concentration of the target compound within a factor of five of the
expected detection limits. The spike samples must be prepared in at least three batches on three
separate calendar dates and analyzed on three separate calendar dates according to the
procedures in Section 11 of this method.

8.8.3 Compute the standard deviation for the replicate blank samples concentrations and multiply
this value by 3.14 to determine the blank MDL (MDLb).

8.8.4 Compute the standard deviation for the replicate spike sample concentrations and multiply
this value by 3.14 to determine the spike MDL (MDLS).

8.8.5 Select the greater of MDLb or MDLS as the MDL for the compound of interest. The results
must demonstrate that the method is able to detect analytes such as ethylene oxide at
concentrations less than 20 pptv and at least 1/10th of the lowest concentration of interest (i.e.,
action-level), whichever is larger. If the MDL does not meet the concentration requirement,
perform corrective action and repeat the MDL determination.

8.8.6 MDL determinations must be repeated at least annually or whenever significant changes
have been made to the sampling or analytical system.

Note: The MDL calculation is based on single-tailed 99th percentile t static at six degrees of
freedom. Additional blank or spike samples would increase the degrees of freedom.

9.0 Quality Control

Table 9-1 in this section lists the quality control (QC) parameters and performance specifications
for this method.

9.1 Second Source Calibration Verification (SSCV) Standard.

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9.1.1 Prepare a humidified SSCV standard in a canister at a concentration in the lower third of
the calibration curve. The SSCV standard must contain all compounds in the calibration mixture.
The SSCV standard must be prepared independently from the calibration standards using a
certified secondary source calibration standard.

9.1.2 Analyze the SSCV after the initial calibration (ICAL). Recovery of each target oHAP in the
SSCV standard must be within ± 30% of the theoretical concentration.

9.2 Continuing Calibration Verification (CCV) Standard. Prepare a humidified CCV standard as
a dilution of a certified standard in a canister at a concentration in the lower third of the
calibration curve. This certified standard must be prepared from the same standard used for the
ICAL standards.

9.2.1 Analyze a CCV for each target oHAP prior to analyzing samples, after every 10 sample
injections, and at the end of the analytical sequence. Prepare a humidified CCV standard as a
dilution of a certified standard in a canister at a concentration in the lower third of the calibration
curve. This certified standard must be prepared from the cylinder used for the ICAL standards.

9.2.2 The internal standard (IS) area responses for each CCV standard must meet the criteria
outlined in Section 10.8.1.5 of this method, and the quantitated concentrations of the target
compounds for each CCV standard must be within ± 30% of the theoretical concentrations as
determined using Equation 3 in Section 12 of this method.

9.2.3 If the CCV is not within specifications, you must invalidate any results after the last
successful CCV. You must investigate and address CCV failures and initiate corrective actions,
including, for example, reanalyzing the CCV, preparing and analyzing a new CCV or standard
canister, and performing a new ICAL

9.3 Blank Analyses. Analysis of all blanks must demonstrate each target compound is < 20 pptv
14.7 psia or undetected (whichever is more stringent) per compound of interest. Unless otherwise
stated, the volume used for analysis of blanks must match the volume of sample to be analyzed.

9.3.1 Instrument Blanks (IB). Analyze an IB at the beginning of the sequence and prior to
analysis of the ICAL standard and daily CCV standard.

9.3.2 Method Blanks (MB). Analyze a laboratory MB prior to and following the ICAL in an
ICAL sequence and prior to analyzing the CCV standard. The MB consists of a canister filled
with humidified (40 to 50% RH) clean diluent gas and is analyzed via the same instrument
method as the standards and field samples in the analytical sequence. Your MB must be the same
diluent used for sample dilution.

9.3.3 Canister Field Blank. Analyze the canister field blank as part of the same analytical
sequence as the accompanying field samples.

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9.3.4 Calibration Blank (CB). Analyze the CB when the ICAL is established and when preparing
any new CCV standard using the same instrument method that was used for standards and field
samples when establishing the ICAL. The CB consists of a canister filled with the humidified (40
to 50% RH) clean diluent gas sourced through the dilution system employed to prepare
standards. For laboratories that do not employ a dynamic or automated static dilution system, the
CB consists of a humidified (40 to 50% RH) canister of the gas used to dilute the calibration
standard.

9.4 Duplicate samples must be analyzed and reported as part of this method. They are used to
evaluate sampling and/or analytical precision.

9.4.1 Field Duplicate. The level of agreement between duplicate field samples is a measure of the
precision achievable for the entire sampling and analysis. Analyze the field duplicate during the
same analytical sequence as the accompanying field sample. The RPD of the precision
measurements should agree within ± 30% when both measurements are > 5 times the MDL. Flag
associated results to indicate if the RPD indicates poor method precision.

9.4.2 Replicate Analysis. The level of agreement between replicate samples is a measure of
precision achievable for the analysis. Analyze at least one replicate analysis for each set of field-
collected samples. The RPD of the precision measurements should agree within ± 25% when
both measurements are > 5 times the MDL. Flag associated results to indicate if the RPD
indicates poor method precision.

Table 9-1. Quality Control Parameters and Performance Specifications

Description

Required

Acceptance

Parameter

and Details

Frequency

Criteria

Corrective Action

Analytical zero-air verification

Test of

At installation prior

Analysis must

Take steps to

instrumentation

to initial use of the

show that any

remove

to demonstrate

instrument.

detected

contamination

cleanliness

target

attributable to the

(positive bias)

compounds in

analytical

by analyzing

the zero-air

instrumentation by

humidified zero

challenge

following the

air; performed

sample are at

manufacturer's

by connecting

response

instructions (e.g.,

the clean

levels that are

analyzing

humidified gas

expected to be

replicates of

sample to the

< 20 pptv or

humidified clean

pre concentrator

not detected.

gas).

to verify that

the analytical

instrument and

all connections

are sufficiently

clean.

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Description

Required

Acceptance



Parameter

and Details

Frequency

Criteria

Corrective Action

Analytical known-standard

Test to

At installation prior

Verifies that

Check for cold

challenge for analytical

demonstrate

to initial use of the

all target

spots in transfer

instrumentation

that the

instrument and with

compounds

line, gas



analytical

instrument's annual

are detected

impurities, sorbent



instrumentation

calibration.

by the system,

traps, GC column,



(preconcentrator



that they

system leaks,



and GC-MS



respond

and/or poor



system) is not



consistently

moisture



causing loss of



upon repeated

management.



compounds



injection, and

Consult instrument



(negative bias).



that they

manufacturer for







exhibit

steps to eliminate







sufficient

bias, as necessary.







response to be









quantifiable at









low









concentrations









(see Section









8.2.2 of this









method).



Zero-air challenge of

After

Prior to initial use,

Each target

(1) Heat and purge

autosamplers associated with

establishing the

upon replacement of

VOC's

any lines,

analytical instrument systems

ICAL, each port

transfer lines, or

concentration

and/or



of the

after analysis of

must be < 20

(2) Rinse with



autosampler is

potentially

pptv or

deionized



tested to

contaminating

preferably not

water, dry, and



demonstrate

samples.

detected (see

purge any lines



cleanliness



Section 8.2.3

that fail.



(positive bias)



of this





by analyzing



method).





humidified zero









air; performed









by connecting









the clean









humidified gas









sample to the









port to verify









that transfer









lines and all









connections are









sufficiently









clean.







26

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Description

Required

Acceptance



Parameter

and Details

Frequency

Criteria

Corrective Action

Known-standard challenge of

After

Prior to initial use

Each target

(1) Heat and purge

autosamplers associated with

establishing the

and upon

VOC's

any lines,

analytical instrument systems

ICAL, each port

replacement of

concentration

and/or



of the

transfer lines.

within ±15%

(2) Rinse with



autosampler is



of theoretical

deionized



tested with a



concentration

water, dry, and



reference



(see Section

purge any lines



standard



8.2.3 of this

that fail.



(approximately



method).





100 to 500









pptv) to









demonstrate









that the









autosampler is









not causing bias









(typically loss









of compounds









or negative









bias).







Canister leak check

Verification that

Prior to initial use

A pressure

(1) Remove from



canisters are

and annually

change > 0.69

service, and



leak-free by

thereafter.

kPa/day (see

(2) Repair canister



performing a



Section 8.3.2

connections



pressure decay



of this

and/or valve.



test of a canister



method).





pressurized to









approximately









203 kPa









absolute (29.4









psia) over the









course of









several days.







Canister zero-air verification

Test of canisters

Initially upon receipt

Upon initial

(1) Clean and retest



to determine

in the laboratory and

analysis after

canisters that



that they are

every 6 months

a minimum of

fail the zero-air



and remain

thereafter.

24 hours and

verification.



acceptably



after 7 days,

(2) Remove



clean (show



each target

canisters from



acceptably low



VOC's

service that



positive bias)



concentration

cannot pass the



over the course



< 20 pptv at

zero-air



of 7 days, by



101.3 kPa

verification



filling with



absolute (14.7

after the



humidified zero



psia).

cleaning



air (not





process.



nitrogen).







27

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Description

Required

Acceptance



Parameter

and Details

Frequency

Criteria

Corrective Action

Known-standard challenge of

Test of canisters

Initially upon receipt

Upon initial

(1) Clean and

canisters for qualification

to determine

in the laboratory and

analysis after

retest canisters



bias by filling

every 3 years

a minimum of

that fail the



with a known

thereafter.

24 hours and

known-



reference



subsequent

standard



standard



analysis at 30

verification.



(approximately



days or

(2) Remove



100 to 500



typical

canisters from



pptv) prepared



laboratory

service that



in humidified



holding time,

cannot pass



zero air (not



each target

known-



nitrogen) and



VOC's

standard



analyzing.



concentration

verification







must remain

after the







within ± 30%

cleaning







of theoretical

process.







concentration









(see Section









8.3.4 of this









method).



Zero-air challenge of sampling

Assessment of

Prior to initial field

Analysis must

(1) Take steps to

devices

positive bias of

deployment and

show that the

remove the



sampling

every six months

target

contamination



system by

thereafter, following

compounds in

attributable to



collecting

maintenance

the zero-air

the sampling



humidified zero

(component

challenge

unit (e.g.,



air through the

replacement), or

sample

purging with



sampling

after collection of

collected

HCF zero air



device/system

potentially

through the

overnight or



and comparing

contaminating

sampling unit

longer).



it to the

samples.

are not > 20

(2) Disassemble



reference



pptv higher

and clean. See



sample



than the

Section 8.6 of



collected



concentration

this method.



upstream of the



in the





sampling



reference





device/system.



sample (see









Section 8.1.5









of this









method).



28

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Description

Required

Acceptance



Parameter

and Details

Frequency

Criteria

Corrective Action

Known-standard challenge of

Assessment of

Prior to initial field

Each target

(1) Take steps to

sampling devices/systems

bias of sampling

deployment and at

VOC's

remove the



system by

least every six

concentration

contamination



collecting a

months thereafter,

within ±15%

attributable to



known

following

of

the sampling



reference

maintenance

concentrations

unit (e.g.,



standard

(component

in the

purging with



(approximately

replacement), or

reference

HCF zero air



100 to 500

after collection of

sample.

overnight or



pptv) through

potentially



longer).



the sampling

contaminating



(2) Disassemble



device/system

samples or damaging



and clean. See



and comparing

sample matrices that



Section 8.6 of



it to the

may impact the



this method.



reference

activity of the flow







standard

path surfaces.







collected









upstream of the









sampling









device/system.







Purge gas check

Analysis of

Verified upon initial

Each target

Replace



canister

setup and in the

VOC's

hydrocarbon trap,



cleaning purge

event of changes in

concentration

catalytic oxidizer,



gas to ensure

gas sourcing or after

< 20 pptv (see

contaminated



contaminants

the replacement of

Section 8.4.1

tubing, etc.



are acceptably

scrubbers such as

of this





low.

hydrocarbon traps

method).







and moisture traps,









or following









maintenance of zero-









air generator.





Canister cleaning blank check

Analysis of a

Every canister from

Upon analysis

(1) Reclean



sample of

each batch of

24 hours after

canister, and/or



humidified

cleaned canisters.

filling, each

(2) Disassemble



diluent gas in a



target VOC's

and clean the



canister after



concentration

components



cleaning to



must meet the

according to



ensure



canister blank

Section 8.6 of



acceptably low



acceptance

this method.



levels of VOCs



criterion in





in the cleaned



Table 2 in





canisters.



Section 17 of









this method









(i.e., <20









pptv at 101.3









kPa absolute,









14.7 psia) (see









Section 8.5 of









this method).



29

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Parameter

Description
and Details

Required
Frequency

Acceptance
Criteria

Corrective Action

Holding time

Duration from
end of sample
collection or
canister
preparation to
analysis.

Each field-collected
or laboratory QC
(standard or blank)
canister.

< 7 days

(1)	Reprepare any
lab standard or
blank.

(2)	Flag the results
of any sample
analyzed
outside of
holding time.

Bromofluorobenzene
instrument tune performance
check

Injection of 1 to
2 nanograms
(ng) BFB for
tune verification
of quadrupole
or ion trap MS
detector.

Prior to ICAL and
prior to each day's
analysis.

Abundance
criteria for
BFB listed in
Table 5 in
Section 17 of
this method
(see Section
10.7.2 of this
method)

(1)	Retune, and/or

(2)	Perform
maintenance.

Retention time (RT)

RT of each IS
and target
compound.

All qualitatively
identified
compounds and
internal standards.

IS compounds
and target
oHAP within
± 2 seconds of
most recent
calibration
check.

Flag data for

possible

invalidation.

Samples - internal standards
(IS)

Deuterated or
other

compounds not
typically found
in ambient air
co-analyzed
with samples to
monitor
instrument
response and
assess matrix
effects.

All laboratory QC
samples, and field-
collected samples.

Area response
for each IS
compound
must be
within ± 30%
of the average
response as
determined
from the most
recent
calibration
check.

Flag data for

possible

invalidation.

30

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Description

Required

Acceptance



Parameter

and Details

Frequency

Criteria

Corrective Action

Initial calibration (ICAL)

Analysis of a

Before sample

Average

(1) Repeat



minimum of

analysis, following

Relative

calibration



five calibration

failed BFB tune

Response

standard analysis.



levels covering

check (as

Factor (RRF)

(2) Repeat



approximately

applicable), failed IS

< 30% RSD

linearity check.



20 to 5000 pptv.

criteria, or failed

and each

(3) Prepare new





CCV criteria;

calibration

calibration





annually, or when

level within

standards as





changes/maintenance

±30% of

necessary and





to the instrument

theoretical

repeat analysis.





affect calibration

concentration;







response.

Relative









Retention









Times (RRTs)









for target









peaks within









0.06 units









from mean









RRT.



Second source calibration

Analysis of a

Immediately after

Measured

(1) Repeat SSCV

verification (SSCV)

secondary

each ICAL.

concentrations

analysis.



source standard



of VOCs must

(2) Reprepare and



in the lower



be within

reanalyze SSCV



third of the



±30% of

standard.



calibration



theoretical





curve to verify



concentration





ICAL accuracy



(see Section





for each target



9.1 of this





analyte.



method).



Continuing calibration

Analysis of a

Prior to analyzing

Measured

(1) Repeat CCV

verification (CCV)

known standard

samples in an

concentrations

analysis.



in the lower

analytical sequence

of VOCs

(2) Repeat ICAL.



third of the

and at the end of a

within ± 30%





calibration

sequence, unless the

of theoretical





curve to verify

sequence begins with

concentration





ongoing

an ICAL;

(see Section





instrument

recommended after

9.2 of this





calibration for

every 10 sample

method).





each target

injections.







analyte.







31

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Description

Required

Acceptance



Parameter

and Details

Frequency

Criteria

Corrective Action

Instrument blank (IB)

Analysis of an

Prior to ICAL and at

Each target

(1) Repeat IB



injection where

the beginning of an

VOC's

analysis.



no sample or

analytical sequence.

concentration

(2) Bakeout



standard is



must be < 20

preconcentrator



introduced to



pptv (see

system and



the



Section 9.3.1

repeat IB



preconcentrator



of this

analysis.



to preliminarily



method).

(3) Replace



demonstrate the





contaminated



carrier gas and





tubing/traps as



instrument are





needed.



sufficiently









clean to begin









analysis.







Method blank (MB)

Canister filled

Prior to and

This must

(1) Repeat analysis.



with clean,

following the ICAL

demonstrate

(2) Reprepare the



humidified

and daily following

acceptably

MB canister and



diluent gas;

the IB/BFB and prior

low carryover

reanalyze.



indicates that

to the initial daily

in the

(3) Check the



target VOCs

ccv/sscv.

analytical

system for leaks.



and potential



system prior





interferences



to analysis of





are at



samples; each





acceptably low



target VOC's





levels in the



concentration





system as a



must be < 20





whole; the MB



pptv (see





is to help assess



Section 9.3.2





overall quality



of this





of the data.



method).



Calibration blank (CB)

Canister filled

Prepare one CB with

CB must be

(1) Reanalyze CB.



with clean,

each set of

sufficiently

(2) Reprepare CB



humidified

calibration standard

clean such

and ICAL canister



diluent gas

canisters and analyze

that little or

standards.



sourced through

with each ICAL

no positive





the standard



bias is





preparation



imparted to





dilution system;



the calibration





indicates that



(see Section





diluent gas and



9.3.3 of this





dilution



method).





apparatus do not









contribute target









VOCs,









imparting a









positive bias to









the ICAL







32

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Description

Required

Acceptance

Parameter

and Details

Frequency

Criteria

Corrective Action

Method precision

Duplicate

Applicable to the

Precision <

(1) Check for

samples:

collection of

30% RPD of

preconcentrator

precision is

samples: one per

target VOCs

volume

determined

sampling day.

in the

measurement

from the

compared

error.

analyzed

samples when

(2) Reanalyze

concentrations

both

primary sample

of collocated

measurements

and collocated

samples.

are > fivefold

duplicate.

MDL (see

(3) Flag data for

Section 9.4 of

possible

this method).

invalidation.

Instrument precision

Precision is

One replicate

Precision <

(1) Check for

determined

analysis to be

25% RPD for

preconcentrator

from repeated

performed with each

target VOCs

volume

analyses of a

sampling day.

when both

measurement

sample from a

measurements

error.

single canister;

are > fivefold

(2) Reanalyze

replicate

MDL (see

primary sample

analyses are

Section 9.4 of

and collocated

used to

this method).

duplicate.

determine

(3) Flag data for

precision of the

possible

analysis

invalidation.

processes and

do not provide

information on

sampling

precision.

Preconcentrator leak check

Pressurize or

Each canister

<3.4 kPa (0.5

Check the

evacuate the

connected to the

psi) change

tightness of all

canister

instrument prior to

per minute or

fittings and

connection to

analysis.

recheck.

verify as leak-

recommended

free.

by the

manufacturer

(see Section

11.4.2 of this

method).

10.0 Calibration and Standardization

10.1 Humidification of Canisters.

10.1.1 Calculate the volume of water you must add to standard and blank canisters to achieve 40
to 50% RH at ambient laboratory temperature. (See Equation 6 in Section 12 of this method).

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10.1.2 Use a bubbler or impinger within the dilution gas stream, add water to the canister, or use
a combination of these two methods to add the calculated volume of deionized water to the
canister necessary to achieve internal RH of approximately 40 to 50% at ambient laboratory
temperature. For direct injection of water into a canister with a syringe, install a high-pressure
PTFE-sealed septum on the canister. For canisters that are to be connected to a gas source for
pressurization via a dynamic or static dilution system, you can add the deionized water to the
valve opening of the evacuated canister prior to connecting to the dilution system. Do not add
water to the canister using a syringe via rubber septum or other materials that may introduce
target or interfering compounds.

10.2 Dynamic Dilution.

10.2.1 Gas Dilution System. The gas dilution system must produce calibration gases whose
measured concentration values are within ± 2% of the predicted values. The predicted values are
calculated based on the certified concentration of the supply gas (Protocol gases, when available,
are recommended for their accuracy) and the gas flow rates (or dilution ratios) through the gas
dilution system.

10.2.2 The gas dilution system must be calibrated and verified per Section 6.10.1 of this method.

10.2.3 Standards Preparation by Dynamic Dilution.

10.2.3.1 Prior to use, power on the dynamic dilution system and allow the diluent and stock
gases to flow through the respective MFC at operating flow rates. Allow gases to flow for at least
the minimum time used during the yearly bias check in Section 6.10.1.3 of this method, to ensure
the concentrations of the oHAPs in the blended gas are stable prior to transferring to the
humidified canister (or directly to the preconcentrator).

10.2.3.2 You must prepare humidified (40 to 50% RH) standards in canisters from low
concentration to high concentration. When changing stock gas flow rate(s) to prepare a different
concentration, allow the calibration gas sufficient time to flow through the system prior to
preparation of the working calibration canister (or delivering the working standard directly to the
preconcentrator).

10.2.3.3 The final pressure of the calibration standard canister must not exceed the maximum
pressure permitted by the preconcentrator.

10.2.2.4 Calculate the final concentration of the diluted standard using Equation 7 in Section 12
of this method.

10.3 Static Dilution.

10.3.1 Static Gas Dilution System. The gas dilution system shall produce calibration gases whose
measured values are within ± 2% of the predicted values. The predicted values are calculated
based on the certified concentration of the supply gases (Protocol gases, when available, are

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recommended for their accuracy) and their partial pressure measurements (or dilution ratios) in
the prepared standard canister.

10.3.2 Static Dilution by Addition of Partial Pressures into a Canister.

10.3.2.1 Connect a pressure transducer or gauge to an evacuated canister to monitor the canister
pressure as you add gases. The pressure transducer or gauge must meet the requirements in
Section 6.5 of this method.

10.3.2.2 Add stock and diluent gases separately through a manifold or by direct connection of the
gas to the standard canister or vessel.

10.3.2.3 Measure the canister pressure before and after standard and diluent gases are bled into
the canister, and input these pressures into the calculation of the dilution factor and final
concentrations.

10.3.2.4 Calculate the final concentration of each target compound in the diluted standard using
Equation 8 in Section 12 of this method.

10.4 Storage of Standards. Standards prepared in canisters at ambient laboratory conditions must
be stored in locations that are free of potential contaminants for up to 7 days.

10.5 Pre-Concentration System Operation. Condition preconcentrator traps when first installed to
eliminate contaminants that act as interferences or chromatographic artifacts, per manufacturer
recommendation. After the recommended conditioning procedure is completed, analyze the IBs
and MBs to verify the preconcentrator system meets the method criteria.

Note: For preconcentrator traps that contain multiple types of sorbent beds, the oven
temperature must not exceed the lowest conditioning temperature of the sor bents contained in
the trap.

10.6 GC-MS System. Optimize GC conditions for compound separation and sensitivity as
indicated by baseline separation for the targeted compounds by establishing GC carrier gas flow
rates, oven temperature program, and instrument run time based on the manufacturer's
recommendations and customize, as needed, to separate the desired target oHAPs.

10.7 MS Tuning/Optimizing and Verification.

10.7.1 General. Tune/optimize the MS (quadrupole, ion trap, or TOF MS) to demonstrate
acceptable performance across the selected ion mass range according to the manufacturer's
specifications upon initial installation of the instrument and following significant preventive
maintenance or repair activities that impact the performance of the GC-MS system (e.g., cleaning
the ion source or analyzer; trimming or replacing the capillary column; and adjusting MS tune or
optimization parameters).

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10.7.2 BFB Tuning Check. Before the ICAL and at least once during every 24-hour period of
analyzing samples, blanks, or calibration standards thereafter, you must conduct a BFB tuning
check for linear quadrupole or ion trap MS instruments. The BFB tuning check may be combined
with the IB.

10.7.2.1 Introduce 1 to 2 ng of BFB into the preconcentrator and analyze the standard using the
preconcentrator parameters established and used for the analysis of calibration standards, QC
samples, and field samples. You must also use the method integration and analysis parameters
employed for routine analysis of standards, QC samples, and field samples.

10.7.2.2 The BFB tuning check must show that the GC-MS system meets the mass spectral ion
abundance criteria listed in Table 2 in Section 17 of this method for the target compounds before
you can use the system for any analysis. If the GC-MS system cannot meet the BFB tuning
criteria, adjust the tuning of the MS or take corrective actions. You must not use this system until
the abundance criteria has been met.

10.8 Internal Standards and Calibration.

Method users must meet acceptance criteria for the calibration and QC listed in the following
section for the suite of target compounds.

10.8.1 Selection and Use of Internal Standards (IS).

10.8.1.1 Select IS compound(s) to be used for oHAP analysis. At a minimum, you must use a
single IS compound. IS compounds must have similar retention times to the compounds being
detected. Typical IS compounds include bromochloromethane; 1,4-difluorobenzene;
chlorobenzene-ds; l,2-dichloroethane-d4; hexane-di4; toluene-dx; and l,2-dichlorobenzene-d4.

10.8.1.2 If using purchased IS stock gases, evaluate the IS upon receipt for the presence of
contaminants that may interfere with the quantitation of target compounds by analyzing
increasing volumes of the IS (e.g., 25, 50, 100, 250 milliliters [mL]) and examining the results
for compound contaminants whose responses increase proportionally with the increasing volume
of IS analyzed. Do not use IS gas standards that fail the MB acceptance criteria.

10.8.1.3 You must add the IS through a dedicated non-sample port in the preconcentrator at the
same concentration for each injection (e.g., standard, sample, blank) to monitor instrument
sensitivity and assess potential matrix effects. Choose the concentration of IS added to each
injection such that the peak area response for the IS compound approximates the area responses
for target compounds in the lower half of the calibration curve range, but that minimally provides
a peak that is on scale and does not exceed the area response of the highest calibration standard.

10.8.1.4 Internal Standard Retention Time (RT). Each IS compound in each sample injection
must be within ±2 seconds of the RT for each IS compound in the most recent calibration.

10.8.1.5 Internal Standard Response. The area response for each IS compound in each injection
(e.g., calibration standard, field sample, blank, CCV) must be within ± 30% of the mean area

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response of the IS compound determined from the ICAL determined using Equation 10 in
Section 12 of this method or most recent calibration check, whichever is most appropriate.

10.8.1.6 Choose the quantitation ion for each IS compound as the most abundant ion (base peak)
unless there is a spectral interference from a coeluting or nearby compound or interference that
impacts the quantitation of the base peak. In such cases, select another abundant ion that is
distinguishable from the other compounds for quantitation.

10.8.1.7 You must invalidate then reanalyze any samples for which the IS area response differs
by more than 30% from the mean IS area response.

10.8.2 Establishing Calibration. Calibrate the GC-MS initially, annually, whenever CCV
standards exceed acceptance criteria, or when the system is out of control as indicated by IS
responses. Prior to calibration, analyze a sufficient number of humidified (40 to 50% RH) HCF
zero air blanks or humidified check standards to verify that instrument sensitivity is stable, as
indicated by IS response.

10.8.2.1 Preparation for Calibration.

10.8.2.1.1 Prepare the calibration curve by preparing standards that bracket the expected
concentration levels at the sampling location(s).

10.8.2.1.2 You must include at least five levels in the ICAL to approximate concentrations of
target oHAPs expected at the deployment location(s), including one level within a factor of five
of the detection limits of the compounds of interest, and another level within 10% of the
compound specific action-level, as defined in the applicable standard.

Note: To establish the calibration curve, the theoretical concentrations of the working
calibration standards must be calculated using the certified concentration from the gas vendor
or neat standard provider. Certificates of analysis for stock standard gas mixtures typically
include both a nominal (or "requested") concentration (e.g., 100ppbv) for each analyte and a
certified concentration (e.g., 108 ppbv), which should be within a specified tolerance (e.g.,
± 10%). These tolerances may permit the certified concentration to differ from the nominal
concentration by 10% to 20%, resulting in final theoretical concentration errors for the working-
level standards when the nominal concentration is input into standard concentration
calculations instead of the certified concentration. Calibration standards prepared with neat
materials must account for the standard purity when calculating the working standard
concentrations.

10.8.2.2 Calibration Curve.

10.8.2.2.1 Following analysis of all calibration standards, prepare a calibration curve for each
target analyte by determining the relative response factor (RRF) of each concentration level.
Following data acquisition for the calibration standards, calculate the RRF of each target
compound in each calibration level using Equation 11 in Section 12 of this method.

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10.8.2.2.2 Choose the quantitation ion for each target compound as the most abundant ion (base
peak) unless there is a spectral interference from a coeluting or nearby compound or interference
that impacts the quantitation of the base peak. In such cases, select another abundant ion that is
distinguishable from the other compounds for quantitation.

10.8.2.2.3 The %RSD of the RRF for each target compound must be < 30%.

10.8.2.2.4 The calculated concentration for each target compound(s) at each calibration level
must be within ± 30% of the theoretical concentration when quantitated against the resulting
calibration curve.

11.0 Analytical Procedures

11.1 Measurement of Canister Receipt Pressure.

11.1.1 Upon receipt at the laboratory, review the sample collection information documented on
the field data page and/or COC form(s) for completeness and accuracy. Compare the canister
label with the sample collection data sheet and verify that the canister and sample IDs are
correct.

11.1.2 Measure and record the canister pressure using a calibrated vacuum/pressure gauge or
transducer. The measured canister absolute pressure must be within ±3.5 kPa (1 in. Hg or 0.5 psi)
of that measured upon collection in the field. Pressure differences exceeding this criterion
indicate the canister has leaked and you must flag the results as invalid.

11.2 Dilution of Canister Samples. A canister must be pressurized to provide sufficient pressure
for removing an aliquot from the canister for analysis. Pressurize the canister with diluent gas to
a pressure less than or equal to the final pressure of the standard gas canisters.

Note: Minimum sample pressures will depend on the size of the canister and the capability of the
preconcentrator to remove the desired aliquot of the sample and will be indicated by the
instrument manufacturer.

11.2.2 Measure the canister pressure using a calibrated vacuum/pressure gauge or pressure
transducer just prior to dilution and immediately following dilution and calculate the canister
dilution correction factor (CDCF) from the two absolute pressure readings (see Equation 12 in
Section 12 of this method).

11.2.3 You must allow diluted canisters to equilibrate for a minimum of 12 hours before
analysis.

11.3 Sample Preconcentration. Draw a measured aliquot of the whole air sample (typically 100
to 1000 mL) from the sample canister by vacuum through a preconcentrator to minimize the
moisture and bulk atmospheric gases (e.g., oxygen, nitrogen, argon, and carbon dioxide) from
the sample aliquot prior to introduction of the target compounds to the GC.

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Note: Preconcentrator instrument manufacturers will typically indicate the optimum factory
default settings for the sample aliquot volume, trapping time, trapping temperature, gas flows,
and additional preconcentration parameters. Adjust each of these variables as neededfor the
target compounds.

11.4 Sample Analysis. You must analyze samples using the same acquisition methods you used
for establishing calibration (i.e., preconcentrator operation parameters, GC oven program, MS
parameters, and integration methods). Field-collected samples and QC samples must be at
ambient laboratory temperature for analysis. You must use approximately the same sample
aliquot volume for all samples unless dilution is required. Adjustment of this sample aliquot
volume requires adjustment of a dilution factor to account for the difference in relative analyzed
volume, as discussed in Section 11.4.4 of this method.

11.4.1 Leak Check of Preconcentrator Connections.

11.4.1.1 Prior to beginning an analytical sequence, including an ICAL sequence, verify each
canister connection as leak-free through the preconcentrator.

11.4.1.2 During the leak check, connect canisters to the autosampler or sample introduction lines
and maintain the canister valves in the closed position.

11.4.1.3 Evacuate each port of the autosampler or sample introduction line and monitor for a
change in pressure for 1 minute. The pressure must not change by more than 0.5 psig/minute.

11.4.1.4 If a sample line fails the leak check, implement corrective actions (e.g., rechecking the
tightness of all fittings) and then retest. Do not perform analysis using any canister connection
that does not pass the leak check.

11.4.1.5 Following the successful leak check, evacuate all autosampler ports or sample
introduction lines, open the canister valves, and document the leak check results in the analysis
records.

11.4.2 Sample Introduction.

11.4.2.1 Prior to each sample analysis sequence, you must connect each sample canister to the
preconcentration unit through a port and verify each canister as having a leak-free connection.

11.4.2.2 Accurately measure the sample aliquot volume for analysis by metering the sample with
an MFC or with the combination of a fixed-volume vessel and a pressure transducer. Sample
introduction volume measurements must be made by the same device as the calibration standards
to ensure that analyzed volumes of samples and standards are consistent.

11.4.3 Analysis of Field Samples. Perform the following steps for readying the system and
performing the GC-MS analytical sequence. Once these checks meet criteria (summarized in
Table 9-1 of this method), verify the instrument calibration by analysis of a CCV and begin
sample analysis.

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11.4.3.1 Perform an air/water check of the MS prior to any analyses to ensure that the system is
acceptably leak-free.

11.4.3.2 Conduct a thorough system bakeout per the manufacturer's instructions for the
preconcentrator and ramp the GC column temperature.

11.4.3.3 Analyze a preliminary IB or perform the BFB instrument tuning check.

11.4.3.4 Analyze a laboratory MB to demonstrate that the system is acceptably clean and that
each target compound is < 20 pptv or undetected (whichever is more stringent) per compound of
interest.

11.4.3.5 Analyze a CCV to verify the instrument calibration.

11.4.3.6 Analyze field samples and additional CCV standards (every 10 samples) and MBs to
complete the sequence, ending with a CCV, as discussed in Section 9.2 of this method.

11.4.4 Sample Dilution. If the on-column concentration of any compound in any sample exceeds
the calibration range, you must dilute the sample for reanalysis by either reducing the sample
aliquot volume for an effective dilution or adding diluent gas to the sample canister to physically
dilute the sample.

11.5 Compound Identification.

11.5.1 After completing data acquisition, examine each chromatogram. Chromatographic peaks
for the target compounds must be appropriately resolved, and integration must not include peak
shoulders or inflections indicative of a coelution. If a peak has not been integrated properly, you
may choose to manually integrate the peak. If a peak has been manually integrated, you must
flag the results and report how and why the peak was manually integrated,

Note: Deconvolution techniques may be available to the operator to help resolve compound
coelutions, depending on the particular instrument and chromatography software package that is
in use.

11.5.2 Identify target compounds qualitatively based on their RT and the relative abundance of
their characteristic ions from the MS by satisfying the following four criteria. If any of the four
criteria are not met, the compound cannot be positively identified.

11.5.2.1 The RT of the compound must be within the RT window of ± 2 seconds of the most
recent calibration check.

11.5.2.2 The relative abundance ratio of qualifier ion response to target ion response for at least
one qualifier ion must be within ± 30% of the average relative abundance ratio from the ICAL.

11.5.2.3 The S:N ratio of the target and qualifier ions must be > 3:1.

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11.5.2.4 The target and qualifier ion peaks must be co-maximized (i.e., peak apexes within one
scan of each other).

11.6 Compound Quantitation. After determining the peak areas, initiate the quantitation process
using the software package of choice to provide quantitative results compound by relating the
area response ratio of each target ion for each target compound to the RRF daily CCV.

11.6.2 Dilution Correction Factors.

11.6.2.1 Calculate an instrument dilution correction factor (IDCF) if you analyzed an aliquot
from the sample canister that is different from the typical analysis volume (as described in
Section 11.4.4 of this method for performing effective dilution) using Equation 14 in Section 12
of this method.

11.6.2.2 Use Equation 15 in Section 12 of this method to determine the final concentration of
each target compound in air by multiplying the instrument-detected concentration by the CDCF
(see Section 11.2 of this method) and the IDCF.

Note: The MDL reported with the final concentration data will be corrected by multiplying the
MDL by the CDCF and IDCF applied to the sample concentrations.

12.0 Data Analysis and Calculations

12.1 Nomenclature. Report results in International System of Units (SI units) unless the
regulatory authority for testing specifies English units. The calculations in this method use the
following nomenclature.

AIS = peak area for quantitation ion of the assigned IS compound.

As = peak area for quantitation ion of the target compound.

Cacc = acceptance limit concentration at measured canister pressure (pptv).

Catm = 20 pptv, acceptance limit concentration at standard atmospheric pressure.

CCCV = measured concentration of the CCV for each target compound (pptv).

Cd = instrument-detected analyte concentration (pptv).

CDCF = canister dilution correction factor.

Cf = final diluted standard concentration (pptv).

Cf = concentration of the target compound in air (pptv).

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CIS = concentration of the assigned IS compound (pptv).

Cs = certified concentration of stock standard (pptv).

Cs = concentration of the target compound (pptv).

Ctheoretical = theoretical concentration of the CCV for each target compound(pptv).

D = sampling duration (min).

dls = density of the neat standard (grams [g]/mL) at temperature of preparation.

Dsat = saturation vapor density of water (milligrams/microliter [mg/|iL]) at ambient laboratory
temperature (refer to Table 3 in Section 17 of this method).

Dw = density of water (1 mg/[xL).

F = flow rate (mL/min) at local conditions.

Fd = flow of diluent gas (mL/min).

Fs = flow of stock standard (mL/min).

IDCF = instrument dilution correction factor.

m = mass of the gas added (g).

mstd = mass of standard material (g).

MW = molecular weight of the gas (g/mol).

n = number of concentration values used to generate the calibration (minimum of 5).
p = purity of neat material as listed on the certificate of analysis (as a decimal).

Pa = atmospheric pressure (kPa absolute) at time of sampling.

Pc = final absolute canister pressure (kPa absolute).

Pi = absolute pressure of a canister sample, cleaning batch blank, etc. prior to dilution kPa
absolute.

Pd = pressure of the canister following dilution (kPa).

Pda = final absolute pressure of manifold and canister after adding diluent (kPa).

42

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Pdb = absolute pressure of manifold and canister before adding diluent (kPa).

Pf = final absolute pressure of canister after adding standard and diluent gases (kPa).

Pi = pressure of the canister immediately preceding dilution (kPa).

Ps = standard ambient pressure (101.3 kPa absolute).

Psa = absolute pressure of canister after adding standard gas (kPa).

Psb = absolute pressure of canister before adding standard gas (kPa).

Pstd = 101.3 kPa absolute, standard atmospheric pressure.

R = gas constant, 8.314 L-kPa/mol-K.

RHd = desired RH level expressed as a decimal.

RPD = relative percent difference.

RRF = relative response factor.

RRFi= relative response factor for the compound.

%RSD = percent relative deviation

RRF = average RRF for the compound.

RT = average RT for the IS compound (min).

RT; = RT for the IS compound for each calibration level (min).

SDrrf= standard deviation of the relative response factors.

T = standard temperature, 293.15 K.

V = volume of the canister (mL) at standard conditions (101.3 kPa absolute and 20 °C).
Vc = nominal internal volume of canister (L).

Vcaic= approximately calculated volume of gas contained in the canister (L).

Vcan = nominal canister volume (L).

Vis = liquid volume of neat standard material at temperature of preparation (mL).

Vt = total volume of standard and diluent gases at 20 °C and 101.3 kPa absolute (L).

43

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Vw = water volume to add to canister (|xL).

Xi = target compound concentration measured in first measurement of the precision pair (pptv).

X2 = target compound concentration measured in second measurement of the precision pair
(pptv).

Y = average area response for the given IS compound.

Yi = area response for the IS for each calibration level.

%Dccv = percent difference of the measured concentration of each target compound in the CCV
standard from the theoretical concentration.

%Recoveryccv = percent recovery of measured versus actual concentration.

12.2 Canister Final Air/Nitrogen Volume (Vcaic).

12.4 Percent Difference of the Measured Concentration of Each Target Compound in the CCV
Standard (%DCCV) from the Theoretical Concentration.

Eq. 1

12.3 Acceptable Concentration Criterion (Cacc).

Eq. 2

0/0Dccv = Cccv Ctheoretical x 100

Ctheoretical

Eq. 3

12.5 Percent Recovery (%Recoveryccv).

%Recoveryccv =

Ctheoretical

Eq. 4

12.6 Relative Percent Difference (RPD).

RPD= (It#) x10°

Eq. 5

12.7 Water Volume to Add to Canister (Vw).

Vw = Dsat .RHd-Vc-^-^-

rs uw

Eq. 6

44

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Note: The equation assumes the density of water to be 1 g/mL and that 100% of the added water to the
canister is in the gas phase. The equation does not correct the density of water for the ambient
temperature.

12.8 Final Concentration of the Diluted Standard (Cf) - Dynamic Dilution.

Note: If you combine multiple gas standards for dilution, the equation denominator is the sum of
all gas flows combinedfor preparing the dilution.

12.9 Final Concentration of the Diluted Standard (Cf) - Static Dilution.

Eq. 8

12.10 Average Retention Time (RT).

Eq. 9

12.11 Average Area Response for the Given IS Compound (Y).

Eq. 10

12.12 Relative Response Factor (RRF).

Eq. 11

12.13 Canister Dilution Correction Factor (CDCF).

CDCF = ^

Eq. 12

Pi

12.14 Instrument-Detected Analyte Concentration (Cd).

At' C1S
Ais -RRF

Eq. 13

12.15 Instrument Dilution Correction Factor (IDCF).

IDCF

Eq. 14

45

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Method 327	03/30/2023

12.16	Concentration of the Target Compound in Air (Cf).

CF= CD ¦ CDCF ¦ IDCF	Eq. 15

12.17	Standard Deviation of the Response Factors (SDrf)

SDm =	Eq 16

12.18 Percent Relative Deviation

%RSD = SDrrf h- RRF X 100	Eq 17

13.0 Method Performance

Table 9-1 of this method lists the QC parameters and performance specifications for this method.
The method performance will be determined by the specific performance of each specific target
compound, laboratory, and the associated equipment.

14.0 Pollution Prevention

[Reserved]

15.0 Waste Management

[Reserved]

16.0 References

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Ambient Air Quality Monitoring Program, U.S. Environmental Protection Agency, EPA-454/B-
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2.	Technical Assistance Document for the National Air Toxics Trends Stations Program,
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3.	Clean Air Act Amendments of 1990, U.S. Congress, Washington, D.C., November 1990.

4.	Method D1356, Standard Terminology Relating to Sampling and Analysis of
Atmospheres.

5.	Method E355-96, Standard Practice for Gas Chromatography Terms and Relationships.

6.	Method D5466, Standard Test Method for Determination of Volatile Organic
Compounds in Atmospheres (Canister Sampling Methodology).

46

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7.	Agilent Technologies, Inc. (2017, July 11). Innovative Cryogen-Free Ambient Air
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8.	ASTM International. (2014). Active Standard ASTM E2655-14: Standard Guide for
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9.	Boyd, R. K., Basic, C., & Bethem, R. A. (2008). Trace Quantitative Analysis by Mass
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10.	Brown, J. (2013, October 22). Choosing the Right Adsorbent for your Thermal
Desorption Gas Chromatography Applications. Presented at the Separation Science Webinar for
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11.	Code of Federal Regulations, 40 CFR Part 58 Appendices D and E, Network Design
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12.	Code of Federal Regulations, 40 CFR Part 136 Appendix B, Definition and Procedure for
the Determination of the Method Detection Limit, Revision 2. Available at
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app/search/%7B%22query%22%3 A%2240%20CFR%20Part%2013 6%20 Appendix%20B%2C%
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15.	Entech Instruments. (2015, August 25). 3-Stage Preconcentration: Why 3-Stage
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17.	Keith, L. H. (1991). Environmental Sampling and Analysis: A Practical Guide. Boca
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18.	Kelly T. J., & Holdren, M. W. (1995). Applicability of canisters for sample storage in the
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19.	McClenny, W. A., Schmidt, S. M., & Kronmiller, K. G. (1999). Variation of the relative
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20.	Nave, C. R. (2017). Relative Humidity. HyperPhysics website, Department of Physics
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21.	Ochiai, N., Daishima, S., & Cardin, D. B. (2003). Long-term measurement of volatile
organic compounds in ambient air by canister-based one-week sampling method. Journal of
Environmental Monitoring, 5(6), 997-1003. doi:10.1039/b307777m.

22.	Ochiai, N., Tsuji, A., Nakamura, N., Daishima, S., & Cardin, D. B. (2002). Stabilities of
58 volatile organic compounds in fused-silica-lined and SUMMA polished canisters under
various humidified conditions. Journal of Environmental Monitoring, 4(6), 879-889.

23.	Restek. (2010). A Guide to Whole Air Canister Sampling: Equipment Needed and
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21, 2019).

24.	U. S. Environmental Protection Agency (EPA). (2017). Quality Assurance Handbook for
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qa/Final%20Handbook%20Document%20l_17.pdf (accessed September 23, 2019).

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27.	U.S. Environmental Protection Agency (EPA). (2015). OSWER Technical Guide for
Assessing and Mitigating the Vapor Intrusion Pathway from Subsurface Vapor Sources to Indoor
Air. EPA Office of Solid Waste and Emergency Response (OSWER) Publication 9200.2-154.
Available at https://www.epa.gov/vaporintrusion/technical-guide-assessing-and-mitigating-
vapor-intrusion-pathway-subsurface-vapor (accessed September 22, 2019).

28.	Wang, D. K., & Austin, C. C. (2006). Determination of complex mixtures of volatile
organic compounds in ambient air: canister methodology. Analytical andBioanalytical
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29.	Batelle. (2016). Technical Assistance Document for the National Air Toxics Trends
Stations Program, Revision 3. Prepared for U.S. EPA by Battelle, Columbus, OH. Available at
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www3.epa.gov/ttn/amtic/files/ambient/airtox/NATTS%20TAD%20Revision%203_FINAL%20
October%202016.pdf (accessed September 22, 2019).

30.	Daughtrey, E. H. Jr., Oliver, K. D., Jacumin, H. H. Jr., & McClenny, W. A. (2004, April
20-22). Supplement to EPA Compendium Method TO-15—Reduction of Method Detection
Limits to Meet Vapor Intrusion Monitoring Needs. Presented at Symposium on Air Quality
Measurement Methods and Technology, Research Triangle Park, NC. Available at
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and Properties of the 189 Clean Air Act Hazardous Air Pollutants. Report EPA/600/R-94/187
prepared under contract 68-DO-0007, work assignment 44, for U.S. EPA by Battelle, Columbus,
OH.

33.	Kelly, T. J., Callahan, P. J., Pleil, J., & Evans, G. F. (1993). Method development and
field measurements for polar volatile organic compounds in ambient air. Environmental Science
& Technology, 27(6), 1146-1153.

34.	McClenny, W. A., Oliver, K. D., & Daughtrey, E.H. Jr. (1995). Analysis of VOCs in
ambient air using multisorbent packings for VOC accumulation and sample drying. Journal of
the Air & Waste Management Association, 45(10), 792-800.

35.	Morris, C., Berkley, R., & Bumgarner, J. (1983). Preparation of multicomponent volatile
organic standards using static dilution bottles. Analytical Letters, 16(20), 1585-1593.

36.	Oliver, K. D., Adams, J. R., Daughtrey, E. H., McClenny, W. A., Yoong, M. J., Pardee,
M. A., Almasi, E. B., & Kirshen, N. A. (1996). Technique for monitoring toxic VOCs in air:

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Sorbent preconcentration, closed-cycle cooler cryofocusing, and GC/MS analysis.

Environmental Science & Technology, 30(6), 1939-1945.

37.	Pleil, J. D., & Lindstrom, A.B. (1995). Collection of a single alveolar exhaled breath for
volatile organic compound analysis. American Journal of Industrial Medicine, 28(1), 109-121.

38.	Pleil, J. D., McClenny, W. A., Holdren, M. W., Pollack, A. J., & Oliver, K. D. (1993).
Spatially resolved monitoring for volatile organic compounds using remote sector sampling.
Atmospheric Environment, Part A, 27(5), 739-747.

39.	Pollack, A. J., Holdren, M. W., & McClenny, W. A. (1991). Multi-adsorbent
preconcentration and gas chromatographic analysis of air toxics with an automated
collection/analytical system. Journal of the Air & Waste Management Association, 41(9), 1213—
1217.

40.	Restek. (2019). Restek Technical Library: Air Sampling. Available at
https://www.restek.com/Technical-Resources/Technical-Library/Air-Sampling (accessed
September 23, 2019).

41.	Stephenson, J., Allen, F., & Slagle, T. (1990). Analysis of volatile organics in air via
water methods. In Proceedings of the 1990 EPA/AWMA International Symposium: Measurement
of Toxic and Related Air Pollutants, EPA 600/9-90-026. Research Triangle Park, NC: U. S.
Environmental Protection Agency.

42.	U.S. Environmental Protection Agency (EPA). (1997). Method TO-14A: Determination
of volatile organic compounds (VOCs) in ambient air using specially prepared canisters with
subsequent analysis by gas chromatography, EPA 600/625/R-96/010b. In Compendium of
Methods for the Determination of Toxic Organic Compounds in Ambient Air, Second Edition.
Cincinnati, OH: U.S. EPA Center for Environmental Research Information, Office of Research
and Development.

43.	Whitaker, D. A., Fortmann, R. C., & Lindstrom, A. B. (1995). Development and testing
of a whole-air sampler for measurement of personal exposure to volatile organic compounds.
Journal of Exposure Analysis & Environmental Epidemiology, 5(1), 89-100.

17.0 Tables, Diagrams, Flow Charts, etc.

Tab

e 1. Canister Cleaning Parameters

Canister Type

Pre-evacuate
Canister

Minimum Air

Purge Gas
Temperature

Humidity

Minimum

No. of
Pressure/
Evacuation
Cycles

Cycle Time

All

Yes

00

o

o

O

50%

5

Varies by system

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Method 327

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a Higher purge gas temperatures may be required depending on the canister type - do not exceed
the manufacturer's recommended maximum temperatures for component parts such as valves
and gauges.

Table 2. BFB Tuning Check Key Ions and Abundance Criteria

Mass

Ion Abundance Criteria"

50

8.0% to 40.0% of m/z 95

75

30.0% to 66.0% of m/z 95

95

Base peak, 100% relative abundance

96

5.0% to 9.0% of m/z 95

173

< 2.0% of m/z 174

174

50.0% to 120.0% of m/z 95

175

4.0% to 9.0% of m/z 174

176

93.0% to 101.0% of m/z 174

177

5.0% to 9.0% of m/z 176

aAll ion abundances must be normalized to m/z 95, the nominal base peak, even though the ion
abundance of m/z 174 may be up to 120% that of m/z 95.

Table 3. Water Saturation Vapor Density at Various Temperatures

Temperature (°C)

Water Saturation Vapor Density (mg/L)a

15

12.8

16

13.6

17

14.4

18

15.3

19

16.3

20

17.3

21

18.3

22

19.4

23

20.6

24

21.8

25

23.1

26

24.4

27

25.9

28

27.3

29

28.9

30

30.5

31

32.2

32

34.0

33

35.8

aValues are generated according to the following formula (Nave, 2017): vapor density (mg/L)
= 5.018 + 0.32321 * T + 8.1847xl0~3 * T2+ 3.1243xl0"4 * T\ where: T = temperature in °C.

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Method 327

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Figure 2. Mechanical Flow Control Device

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Method 327

03/30/2023

Particulate Filler

How Controller

Bill*

Figure 3. Method 327 Sampler

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Method 327

03/30/2023

Method 327 Field Data Page

Sazopliae Personnel



S'iruplir.g Location ID



Loai!7-d« 1

Latitude 1

Sampling EquipmeatlafbrmatMB;

S amplinE C aniiter ID



Sampling Canister Received Date



SamplisE Canister Clean Data



S ampLiaE C aniiter Pressure Readme



Simper.j Dance ID



Reference Flew Meter S (if applicable)



Rrfutr.ce FLew Meter Calibration Date



Samplinr Deuce Excsct'd Flew Rite



Sampling Device Actual FIotv Rate (if applicable)



SamuIiaE Device Flow Ad'usted :Yti Ko)



Sanliag Information

Sample Date



Leak Chedc (Date Time)



Leak Chick Raiult; iPatiFiil)



Start Time



Start Yacuuxtt/Pressare



Comment!

End Time

End VaEimm.'Pressure

Commmti:

Cnstody Transfer

Relinquished/Received

Name

Signature

Date

























Comments:

Figure 4. Example Field Data Page

54

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